JLG G12-55A Service Manual

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Page 1

Service Manual

Models

G10-55A

G12-55A

AccuPlace

31200452

Original

January 20, 2009

An Oshkosh Corporation Company

Page 2

Page 3

EFFECTIVITY PAGE

January 20, 2009 - A - Original Issue Of Manual

31200452 G10-55A & G12-55A AccuPlace i

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EFFECTIVITY PAGE

G10-55A & G12-55A AccuPlace 31200452-ii

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SECTION CONTENTS

Section Subject Page

Section 1

Safety Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.2 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.3 Operation & Safety Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.4 Do Not Operate Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.5 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.6 Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3

1.7 Safety Decals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4

Section 2

General Information and Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

2.1 Replacement Parts and Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2

2.2 Torques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3

2.3 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6

2.4 Fluid and Lubricant Capacities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8

2.5 Service and Maintenance Schedules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9

2.6 Lubrication Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11

Section 3

Boom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1

3.1 Boom System Component Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2

3.2 Boom System - Four Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.3 Boom Assembly Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.4 Boom Extend and Retract Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9

3.5 Boom Section Separation Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14

3.6 Hydraulic Sub-Assembly Removal/Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14

3.7 Boom Wear Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17

3.8 Quick Switch Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18

3.9 Forks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18

3.10 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.19

Section 4

Cab and Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1

4.1 Operator’s Cab and Covers Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2

4.2 Operator’s Cab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.3

4.3 Cab Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.4 Cab Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7

4.5 Cab Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9

Section 5

Axles, Drive Shafts, Wheels and Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1

5.1 Axle, Drive Shaft and Wheel Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5.2

5.2 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3 Axle Assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.4 Drive Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.5 Wheels and Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.10

5.6 Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11

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5.7 Towing a Disabled machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11

Section 6

Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.1

6.1 Transmission Assembly Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2

6.2 Transmission Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.3 Transmission Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.4 Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.5 Transmission Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.7

Section 7

Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1

7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2

7.2 Engine Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4

7.3 Engine Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6

7.4 Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.6

7.5 Engine Exhaust System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8

7.6 Air Cleaner Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.7 Engine Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.8 Torque Convertor Diaphragm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11

7.9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.12

Section 8

Hydraulic System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1

8.1 Hydraulic Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2

8.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3

8.3 Hydraulic Pressure Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4

8.4 Hydraulic Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.5

8.5 Hydraulic System Schematics and Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7

8.6 Hydraulic Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12

8.7 Engine Implement Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13

8.8 Control Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.14

8.9 Hydraulic Piston Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.22

8.10 Hydraulic Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.24

Section 9

Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1

9.1 Electrical Component Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3

9.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4

9.3 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4

9.4 Fuses and Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4

9.5 Control Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.7

9.6 Electrical System Schematics And Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.15

9.7 Engine Start Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.23

9.8 Charging Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9.24

9.9 Window Wiper/Washer Windshield Wiper Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.25

9.10 Cab Heater and Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.26

9.11 Solenoids, Senders and Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.27

9.12 Display Monitor and Gauges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.35

9.13 Dash Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9.36

9.14 Engine Indicator Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.38

9.15 Hand Held Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.39

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Section 1

Safety Practices

Contents

PARAGRAPH TITLE PAGE

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.3 Operation & Safety Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.4 Do Not Operate Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2

1.5 Safety Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.5.1 Safety Alert System and Signal Words . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.6 Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.6.1 Personal Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.6.2 Equipment Hazards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3

1.6.3 General Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4

1.6.4 Operational Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4

1.7 Safety Decals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4

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Safety Practices

1.1 INTRODUCTION

This service manual provides general directions for accomplishing service and repair procedures. Following the procedures in this manual will help assure safety and equipment reliability.

Read, understand and follow the information in this manual, and obey all locally approved safety practices, procedures, rules, codes, regulations and laws.

These instructions cannot cover all details or variations in the equipment, procedures, or processes described, nor provide directions for meeting every possible contingency during operation, maintenance, or testing. When additional information is desired consult the local JLG distributor.

Many factors contribute to unsafe conditions: carelessness, fatigue, overload, inattentiveness, unfamiliarity, even drugs and alcohol, among others. For optimal safety, encourage everyone to think, and to act, safely.

Appropriate service methods and proper repair procedures are essential for the safety of the individual doing the work, for the safety of the operator, and for the safe, reliable operation of the machine. All references to the right side, left side, front and rear are given from the operator’s seat looking in a forward direction.

Supplementary information is available from JLG in the form of Service Bulletins, Service Campaigns, Service Training Schools, the JLG website, other literature, and through updates to the manual itself.

1.2 DISCLAIMER

All information in this manual is based on the latest product information available at the time of publication. JLG reserves the right to make changes and improvements to its products, and to discontinue the manufacture of any product, at its discretion at any time without public notice or obligation.

1.3 OPERATION & SAFETY MANUAL

The mechanic must not operate the machine until the Operation & Safety Manual has been read & understood, training has been accomplished and operation of the machine has been completed under the supervision of an experienced and qualified operator.

An Operation & Safety Manual is supplied with each machine and must be kept in the manual holder located in the cab. In the event that the Operation & Safety Manual is missing, consult the local JLG distributor before proceeding.

1.4 DO NOT OPERATE TAGS

Place Do Not Operate Tags on the ignition key switch and the steering wheel before attempting to perform any service or maintenance. Remove key and disconnect battery leads.

1.2

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Safety Practices

1.5 SAFETY INFORMATION

To avoid possible death or injury, carefully read, understand and comply with all safety messages.

In the event of an accident, know where to obtain medical assistance and how to use a first-aid kit and fire extinguisher/fire suppression system. Keep emergency telephone numbers (fire department, ambulance, rescue squad/paramedics, police department, etc.) nearby. If working alone, check with another person routinely to help assure personal safety.

1.5.1 Safety Alert System and Signal Words

DANGER

DANGER indicates an imminently hazardous situation

which, if not avoided, will result in death or serious injury.

WARNING

WARNING indicates a potentially hazardous situation

which, if not avoided, could result in death or serious injury.

CAUTION

CAUTION indicates a potentially hazardous situation

which, if not avoided, may result in minor or moderate injury.

1.6 SAFETY INSTRUCTIONS

Following are general safety statements to consider before performing maintenance procedures on the telehandler. Additional statements related to specific tasks and procedures are located throughout this manual and are listed prior to any work instructions to provide safety information before the potential of a hazard occurs.

For all safety messages, carefully read, understand and follow the instructions before

1.6.1 Personal Hazards

PERSONAL SAFETY GEAR: Wear all the protective clothing and personal safety gear necessary to perform the job safely. This might include heavy gloves, safety glasses or goggles, filter mask or respirator, safety shoes or a hard hat.

LIFTING: NEVER lift a heavy object without the help of at least one assistant or a suitable sling and hoist.

1.6.2 Equipment Hazards

LIFTING OF EQUIPMENT: Before using any lifting equipment (chains, slings, brackets, hooks, etc.), verify that it is of the proper capacity, in good working order, and is properly attached.

NEVER stand or otherwise become positioned under a suspended load or under raised equipment. The load or equipment could fall or tip.

DO NOT use a hoist, jack or jack stands only to support equipment. Always support equipment with the proper capacity blocks or stands properly rated for the load.

HAND TOOLS: Always use the proper tool for the job; keep tools clean and in good working order, and use special service tools only as recommended.

proceeding.

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Safety Practices

1.6.3 General Hazards

SOLVENTS: Only use approved solvents that are known to be safe for use.

HOUSEKEEPING: Keep the work area and operator’s cab clean, and remove all hazards (debris, oil, tools, etc.).

FIRST AID: Immediately clean, dress and report all injuries (cuts, abrasions, burns, etc.), no matter how minor the injury may seem. Know the location of a First Aid Kit, and know how to use it.

CLEANLINESS: Wear eye protection, and clean all components with a high-pressure or steam cleaner before attempting service.

When removing hydraulic components, plug hose ends and connections to prevent excess leakage and contamination. Place a suitable catch basin beneath the machine to capture fluid run-off.

Check and obey all Federal, State and/or Local regulations regarding waste storage, disposal and recycling.

1.6.4 Operational Hazards

ENGINE: Stop the engine before performing any service unless specifically instructed otherwise.

VENTILATION: Avoid prolonged engine operation in enclosed areas without adequate ventilation.

SOFT SURFACES AND SLOPES: NEVER work on a machine that is parked on a soft surface or slope. The machine must be on a hard level surface, with the wheels blocked before performing any service.

FLUID TEMPERATURE: NEVER work on a machine when the engine, cooling or hydraulic systems are hot. Hot components and fluids can cause severe burns. Allow systems to cool before proceeding.

FLUID PRESSURE: Before loosening any hydraulic or diesel fuel component, hose or tube, turn the engine OFF. Wear heavy, protective gloves and eye protection. NEVER check for leaks using any part of your body; use a piece of cardboard or wood instead. If injured, seek medical attention immediately. Diesel fluid leaking under pressure can explode. Hydraulic fluid and diesel fuel leaking under pressure can penetrate the skin, cause infection, gangrene and other serious personal injury.

Relieve all pressure before disconnecting any component, part, line or hose. Slowly loosen parts and allow release of residual pressure before removing any part or component. Before starting the engine or applying pressure, use components, parts, hoses and pipes that are in good condition, connected properly and are tightened to the proper torque. Capture fluid in an

appropriate container and dispose of in accordance with prevailing environmental regulations.

RADIATOR CAP: The cooling system is under pressure, and escaping coolant can cause severe burns and eye injury. To prevent personal injury, NEVER remove the radiator cap while the cooling system is hot. Wear safety glasses. Turn the radiator cap to the first stop and allow pressure to escape before removing the cap completely. Failure to follow the safety practices could result in death or serious injury.

FLUID FLAMABILTITY: DO NOT service the fuel or hydraulic systems near an open flame, sparks or smoking materials.

NEVER drain or store fluids in an open container. Engine fuel and hydraulic fluid are flammable and can cause a fire and/or explosion.

DO NOT mix gasoline or alcohol with diesel fuel. The mixture can cause an explosion.

PRESSURE TESTING: When conducting any test, only use test equipment that is correctly calibrated and in good condition. Use the correct equipment in the proper manner, and make changes or repairs as indicated by the test procedure to achieve the desired result.

LEAVING MACHINE: Lower the forks or attachment to the ground before leaving the machine.

TIRES: Always keep tires inflated to the proper pressure to help prevent tipover. DO NOT over-inflate tires.

NEVER use mismatched tire types, sizes or ply ratings. Always use matched sets according to machine specifications.

MAJOR COMPONENTS: Never alter, remove, or substitute any items such as counterweights, tires, batteries or other items that may reduce or affect the overall weight or stability of the machine.

BATTERY: DO NOT charge a frozen battery.Charging a frozen battery may cause it to explode. Allow the battery to thaw before jump-starting or connecting a battery charger.

1.7 SAFETY DECALS

Check that all safety decals are present and readable on the machine. Refer to the Operation & Safety Manual supplied with machine for information.

1.4

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Section 2

General Information and Specifications

Contents

PARAGRAPH TITLE PAGE

2.1 Replacement Parts and Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2

2.2 Torques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3

2.2.1 ASTM Fastener Torque Chart (English) . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3

2.2.2 ASTM Fastener Torque Chart (Metric) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4

2.2.3 Metric Fastener Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5

2.3 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6

2.3.1 Travel Speeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6

2.3.2 Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6

2.3.3 Engine Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6

2.3.4 Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7

2.4 Fluid and Lubricant Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8

2.5 Service and Maintenance Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9

2.5.1 10, 1st 100 & 50 Hour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9

2.5.2 250, 500, 1000 & 1500 Hour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10

2.6 Lubrication Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11

G10-55A & G12-55A AccuPlace

2.1

Page 12

General Information and Specifications

2.1 REPLACEMENT PARTS AND WARRANTY INFORMATION

Before ordering parts or initiating service inquiries, make note of the machine serial number. The machine serial number plate (1) is located as indicated in the figure.

MY1000

Note: The replacement of any part on this machine with any other than JLG authorized replacement parts can adversely affect the performance, durability, or safety of the machine, and will void the warranty. JLG disclaims liability for any claims or damages, whether regarding property damage, personal injury or death arising out of the use of unauthorized replacement parts.

A warranty registration form must be filled out by the JLG distributor, signed by the purchaser and returned to JLG when the machine is sold and/or put into use.

Registration activates the warranty period and helps to assure that warranty claims are promptly processed. To guarantee full warranty service, verify that the distributor has returned the business reply card of the warranty registration form to JLG.

2.2

G10-55A & G12-55A AccuPlace

Page 13

2.2 TORQUES

2.2.1 ASTM Fastener Torque Chart (English)

WITH

PATCH

LOC-WEL

TORQUE

PATCH

LOC-WEL

WITHOUT

SOCKET HEAD

General Information and Specifications

UNBRAKO 1960 SERIES

SAE GRADE 8 BOLTS & GRADE 8 NUTS

& SOCKET HEAD CAP SCREWS

LOAD

CLAMP

LOCTITE

TORQUE

DRY OR

LOAD

CLAMP

LOCTITE

TORQUE

271

242 OR

262

LUB

263

LOCTITE

271

242 OR

262

LUB

VALUES FOR ZINC PLATED / YELLOW CHROMATE FASTENERS ONLY UNPLATED CAP SCREWS

GRADE 2 NUTS

SAE GRADE 5 BOLTS &

DRY OR

CLAMP

TENSILE

BOLT

THDS.

263

LOCTITE

LOAD

AREA

STRESS

DIA.

PER

INCH

SIZE

G10-55A & G12-55A AccuPlace

IN SQ. IN. LB. IN-LB IN-LB IN-LB IN-LB LB. IN-LB. IN-LB IN-LB IN-LB LB. IN-LB IN-LB

0.00604 380 8 6 — — 540 12 9 — — — — —

0.1120

48 0.00661 420 9 7 — — 600 13 10 — — — — —632

0.00909 580 16 12 — — 820 23 17 — — — — —

0.1380

40 0.01015 610 18 13 — — 920 25 19 — — — — —832

0.01400 900 30 22 — — 1260 41 31 — — — — —

0.1640

36 0.01474 940 31 23 — — 1320 43 32 — — — — —1024

0.01750 1120 43 32 — — 1580 60 45 — — — — —

0.1900

32 0.02000 1285 49 36 — — 1800 68 51 — — — — —

0.0318 2020 96 75 — 105 2860 144 108 — 160 3180 160 168

0.2500

28 0.0364 2320 120 86 — 135 3280 168 120 — 185 3640 168 178

1/4

0.6060 38600 640 480 579 675 51500 900 680 687 990 60600 865 950

0.7630 42300 800 600 714 840 68700 1280 960 1030 1400 76300 1240 1365

0.9690 53800 1120 840 1009 1175 87200 1820 1360 1453 2000 96900 1750 1925

1.1550 64100 1460 1100 1322 1525 104000 2380 1780 1907 2625 115500 2320 2550

12 1.0730 59600 1240 920 1118 1300 96600 2000 1500 1610 2200 107300 1880 2070

1.3750

12 1.3150 73000 1680 1260 1506 1750 118100 2720 2040 2165 3000 131500 2440 2685

1-3/8

1.4050 78000 1940 1460 1755 2025 126500 3160 2360 2530 3475 140500 3040 3345

1.5000

1-1/2

12 1.5800 87700 2200 1640 1974 2300 142200 3560 2660 2844 3925 158000 3270 3600

Note: These torque values do not apply to cadmium plated fasteners.

0.0524 3340 17 13 16 19 4720 25 18 22 30 5240 25 28

0.0775 4940 30 23 28 35 7000 45 35 40 50 7750 45 50

0.1063 6800 50 35 45 55 9550 70 55 63 80 10630 70 77

0.1419 9050 75 55 68 85 12750 110 80 96 120 14190 110 120

0.1820 11600 110 80 98 120 16400 150 110 139 165 18200 155 170

0.2260 14400 150 110 135 165 20350 220 170 180 240 22600 210 231

0.3340 21300 260 200 240 285 30100 380 280 301 420 33400 365 400

0.4620 29400 430 320 386 475 41600 600 460 485 660 46200 585 645

IN SQ. IN. LB. FT-LB FT-LB FT-LB FT-LB LB. FT-LB FT-LB FT-LB FT-LB LB. FT-LB FT-LB

0.3125

0.3750

0.4375

0.5000

0.5625

0.6250

0.7500

24 0.0580 3700 19 14 17 21 5220 25 20 25 30 5800 27 30

24 0.0878 5600 35 25 32 40 7900 50 35 45 55 8780 50 55

20 0.1187 7550 55 40 50 60 10700 80 60 70 90 11870 75 82

20 0.1599 10700 90 65 80 100 14400 120 90 108 130 15990 115 127

18 0.2030 12950 120 90 109 135 18250 170 130 154 190 20300 165 182

18 0.2560 16300 170 130 153 190 23000 240 180 204 265 25600 220 242

16 0.3730 23800 300 220 268 330 33600 420 320 336 465 37300 400 440

5/16

3/8

7/16

1/2

9/16

5/8

3/4

0.8750

14 0.5090 32400 470 350 425 520 45800 660 500 534 725 50900 635 700

7/8

1.0000

12 0.6630 42200 700 530 633 735 59700 1000 740 796 1100 66300 915 1000

1.1250

12 0.8560 47500 880 660 802 925 77000 1440 1080 1155 1575 85600 1380 1520

1-1/8

1.2500

1-1/4

2.3

Page 14

General Information and Specifications

2.2.2 ASTM Fastener Torque Chart (Metric)

WITH

PATCH

LOC-WEL

TORQUE

PATCH

LOC-WEL

WITHOUT

SOCKET HEAD

UNBRAKO 1960 SERIES

LOAD

CLAMP

271

242 OR

LOCTITE

262

LOCTITE

TORQUE

LUB

263

DRY OR

LOCTITE

& SOCKET HEAD CAP SCREWS

SAE GRADE 8 BOLTS & GRADE 8 NUTS

VALUES FOR ZINC PLATED / YELLOW CHROMATE FASTENERS ONLY UNPLATED CAP SCREWS

LOAD

CLAMP

271

242 OR

LOCTITE

262

LOCTITE

TORQUE

LUB

GRADE 2 NUTS

SAE GRADE 5 BOLTS &

DRY OR

263

LOCTITE

2.4

LOAD

CLAMP

AREA

0.00604 380 .8 .8 — — 540 1.4 1.0 — — — — —

0.00909 580 1.8 1.4 — — 820 2.6 2.0 — — — — —

0.01400 900 3.4 2.4 — — 1260 4.6 3.4 — — — — —

40 0.01015 610 2.0 1.6 — — 920 2.8 2.2 — — — — —832

0.1640

36 0.01474 940 3.4 2.6 — — 1320 5 3.6 — — — — —1024

0.01750 1120 5 3.6 — — 1580 7 5 — — — — —

0.1900

32 0.02000 1285 6 4 — — 1800 8 6 — — — — —

STRESS

TENSILE

IN SQ. IN. LB. N, m N, m N, m N, m LB. N, m N, m N, m N, m LB. N, m N, m

DIA.

BOLT

PER

THDS.

SIZE

0.1120

0.1380

48 0.00661 420 1.0 .8 — — 600 1.5 1.0 — — — — —632

INCH

0.0318 2020 11 8 — 12 2860 16 12 — 18 3180 18 19

0.2500

28 0.0364 2320 14 10 — 15 3280 19 14 — 21 3640 19 20

1/4

IN SQ. IN. LB. N, m N, m N, m N, m LB. N, m N, m N, m N, m LB. N, m N, m

0.0524 3340 23 18 22 26 4720 34 24 30 41 5240 34 38

0.3125

24 0.0580 3700 26 19 23 28 5220 34 27 34 41 5800 37 41

5/16

0.0775 4940 41 31 38 47 7000 61 47 54 68 7750 61 68

0.3750

24 0.0878 5600 47 34 43 54 7900 68 47 61 75 8780 68 75

3/8

0.1063 6800 68 47 61 75 9550 95 75 85 108 10630 95 104

0.4375

20 0.1187 7550 75 54 68 81 10700 108 81 95 122 11870 102 111

7/16

0.1419 9050 102 75 92 115 12750 149 108 130 163 14190 149 163

0.5000

20 0.1599 10700 122 88 108 136 14400 163 122 146 183 15990 156 172

1/2

0.1820 11600 149 108 133 163 16400 203 149 188 224 18200 210 230

0.5625

18 0.2030 12950 163 122 148 183 18250 230 176 209 258 20300 224 247

9/16

0.2260 14400 203 149 183 224 20350 298 230 244 325 22600 285 313

0.6250

18 0.2560 16300 230 176 207 258 23000 325 244 277 359 25600 298 328

5/8

0.3340 21300 353 271 325 386 30100 515 380 408 569 33400 495 542

0.7500

16 0.3730 23800 407 298 363 447 33600 569 434 456 630 37300 542 597

3/4

0.4620 29400 583 434 523 644 41600 813 624 658 895 46200 793 874

0.8750

14 0.5090 32400 637 475 576 705 45800 895 678 724 983 50900 861 949

7/8

0.6060 38600 868 651 785 915 51500 1220 922 931 1342 60600 1173 1288

1.0000

12 0.6630 42200 949 719 858 997 59700 1356 1003 1079 1491 66300 1241 1356

0.7630 42300 1085 813 968 1139 68700 1735 1302 1396 1898 76300 1681 1851

1.1250

1-1/8

12 0.8560 47500 1193 895 1087 1254 77000 1952 1464 1566 2135 85600 1871 2061

0.9690 53800 1518 1139 1368 1593 87200 2468 1844 1970 2712 96900 2373 2610

1.2500

1-1/4

12 1.0730 59600 1681 1247 1516 1763 96600 2712 2034 2183 2983 107300 2549 2807

1.1550 64100 1979 1491 1792 2068 104000 3227 2413 2586 3559 115500 3145 3457

1.3750

1-3/8

12 1.3150 73000 2278 1708 2042 2373 118100 3688 2766 2935 4067 131500 3308 3640

1.4050 78000 2630 1979 2379 2745 126500 4284 3200 3430 4711 140500 4122 4535

1.5000

1-1/2

12 1.5800 87700 2983 2224 2676 3118 142200 4827 3606 3856 5322 158000 4433 4881

Note: These torque values do not apply to cadmium plated fasteners.

G10-55A & G12-55A AccuPlace

Page 15

General Information and Specifications

2.2.3 Metric Fastener Torque Chart

VALUES FOR ZINC PLATED / YELLOW CHROMATE FASTENERS ONLY

CLASS 8.8 METRIC BOLTS &

CLASS 8 METRIC NUTS

TORQUE

LUB

LOCTITE

262

LOCTITE

242 OR

271

CLAMP

SIZE PITCH

TENSILE

STRESS

AREA

CLAMP

LOAD

DRY OR LOCTITE

263

sq. mm KN N, m N, m N, m N, m KN N, m N, m N, m N, m

3 .5 5.03 2.19 1.3 1.0 1.2 1.4 3.13 1.9 1.4 1.5 2.1

3.5 .6 6.78 2.95 2.1 1.6 1.9 2.3 4.22 3.0 2.2 2.4 3.3

4 .7 8.78 3.82 3.1 2.3 2.8 3.4 5.47 4.4 3.3 3.5 4.8

5 .8 14.2 6.18 6.2 4.6 5.6 6.8 8.85 8.9 6.6 7.1 9.7

6 1 20.1 8.74 11 7.9 9.4 12 12.5 15 11 12 17

7 1 28.9 12.6 18 13 16 19 18 25 19 20 28

81.2536.615.92519232822.837272940

10 1.5 58.0 25.2 50 38 45 55 36.1 72 54 58 79

12 1.75 84.3 36.7 88 66 79 97 52.5 126 95 101 139

14 2 115 50.0 140 105 126 154 71.6 200 150 160 220

16 2 157 68.3 219 164 197 241 97.8 313 235 250 344

18 2.5 192 83.5 301 226 271 331 119.5 430 323 344 473

20 2.5 245 106.5 426 320 383 469 152.5 610 458 488 671

22 2.5 303 132.0 581 436 523 639 189.0 832 624 665 915

24 3 353 153.5 737 553 663 811 220.0 1060 792 845 1170

27 3 459 199.5 1080 810 970 1130 286.0 1540 1160 1240 1690

30 3.5 561 244.0 1460 1100 1320 1530 349.5 2100 1570 1680 2310

33 3.5 694 302.0 1990 1490 1790 2090 432.5 2600 2140 2280 2860

36 4 817 355.0 2560 1920 2300 2690 509.0 3660 2750 2930 4020

42 4.5 1120 487.0 4090 3070 3680 4290 698.0 5860 4400 4690 6440

CLASS 10.9 METRIC BOLTS &

CLASS 10 METRIC NUTS

LOAD

DRY OR LOCTITE

263

LUB

TORQUE

LOCTITE

262

LOCTITE

242 OR

271

Note: These torque values do not apply to cadmium plated fasteners.

G10-55A & G12-55A AccuPlace

METRIC CLASS 8.8METRIC CLASS 10.

2.5

Page 16

General Information and Specifications

2.3 SPECIFICATIONS

2.3.1 Travel Speeds

G10-55A G12-55A

First Gear 3.4 mph (5,4 km/h) 3.5 mph (5,6 km/h)

Second Gear 6.1 mph (9,8 km/h) 6.3 mph (10,1 km/h)

Third Gear 13.8 mph (22,2 km/h) 14.1 mph (22,7 km/h)

Fourth Gear 20.0 mph (32,2 km/h) 20.4 mph (32,8 km/h)

2.3.2 Electrical System

Battery:

Type, Rating 12 BCI, Negative (-) Ground, Maintenance Free

Quantity 1

Reserve Capacity 1,000 Cold Cranking Amps @ 0° F (-18° C)

Group/Series Group 31

Alternator 12V, 95 Amps

2.3.3 Engine Performance Specifications

Description G10-55A G12-55A

Engine Make/Model Perkins 1104D - 125HP Perkins 1104D - 142 HP

Displacement 269 in³ (4,4 liters) 269 in³ (4,4 liters)

Low Idle 1000 rpm 900 rpm

High Idle 2,400 to 2,650 rpm 2,400 to 2,650 rpm

Horsepower 125 HP (93 kW) @ 2400 rpm 142 HP (104 kW) @ 2400 rpm

Peak Torque Not Available at Publication 410 lb-ft (556 Nm) @ 1400 rpm

Fuel Delivery Fuel Injection Fuel Injection

Air Cleaner Dry Type, Replaceable Primary and

Safety Elements

Dry Type, Replaceable Primary and

Safety Elements

2.6

G10-55A & G12-55A AccuPlace

Page 17

General Information and Specifications

2.3.4 Tires

Note: Standard wheel lug nut torque is 350-400 lb-ft (475-542 Nm).

a. G10-55A

Size Tire Type Minimum Ply/

Fill Type Pressure

Star Rating

14.00 x 24 G-2/L-2 Bias Ply Traction 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 720 lb foam

14.00 x 24 G-3/L-3 Bias Ply Rock 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 720 lb foam

14.00 x 24 G-2/L-2 Radial 1 Star Pneumatic 70 psi (4,8 bar)

approx. 720 lb foam

14.00 x 24 Solid N/A Solid Rubber N/A

17.50 x 25 G-2/L-2 Bias Ply Traction 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 785 lb foam

17.50 x 25 G-3/L-3 Bias Ply Rock 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 785 lb foam

17.50 x 25 G-2/L-2 Radial 1 Star Pneumatic 70 psi (4,8 bar)

approx. 785 lb foam

b. G12-55A

Size Tire Type Minimum Ply/

Fill Type Pressure

Star Rating

14.00 x 24 Solid N/A Solid Rubber N/A

17.50 x 25 G-2/L-2 Bias Ply Traction 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 785 lb foam

17.50 x 25 G-3/L-3 Bias Ply Rock 12 Ply Pneumatic 65 psi (4,5 bar)

approx. 785 lb foam

17.50 x 25 G-2/L-2 Radial 1 Star Pneumatic 70 psi (4,8 bar)

approx. 785 lb foam

G10-55A & G12-55A AccuPlace

2.7

Page 18

General Information and Specifications

2.4 FLUID AND LUBRICANT CAPACITIES

Engine Crankcase Oil

Capacity with Filter Change - Perkins 7 quarts (6,5 liters)

Oil Type 15W-40 CE

Fuel Tank

Capacity 38 gallons (144 liters)

Type of Fuel Low Sulfur Diesel #2

Cooling System

System Capacity - Perkins 20.5 quarts (19,4 liters)

Overflow Bottle Capacity 3 quarts (2,8 liters)

Type of Fluid 50/50 ethylene glycol & water

Coolant Conditioner (refer engine manual) 0.5 quarts (0,47 liters)

Transmission

Capacity with Filter Change 4.23 gallons (16 liters)

Type of Fluid Mobilfluid

424 Tractor Hydraulic Fluid (ISO 46)

Transfer Case

Capacity 1.5 quarts (1,4 liters)

Type of Fluid Mobilfluid

424 Tractor Hydraulic Fluid (ISO 46)

Axles

Differential Housing Capacity Front Axle - 15.8 quarts (15 liters)

Rear Axle - 16.9 quarts (16 liters)

Wheel End Capacity 2 quarts (1,9 liters)

Type of Fluid Mobilfluid

424 Tractor Hydraulic Fluid (ISO 46)

Hydraulic System

System Capacity G10-55A - 63 gallons (238 liters)

G12-55A - 65 gallons (246 liters)

Reservoir Capacity 38 gallons (144 liters)

Auxiliary Hydraulic Circuit Max Flow 16 gpm (72,7 lpm)

Type of Fluid Mobilfluid

424 Tractor Hydraulic Fluid

2.8

G10-55A & G12-55A AccuPlace

Page 19

2.5 SERVICE AND MAINTENANCE SCHEDULES

2.5.1 10, 1st 100 & 50 Hour

EVERY

General Information and Specifications

Check Fuel

Level

Check

Transmission

Oil Level

100

Change Axle Oil

(

Check Wheel

Lug Nut

Torque

)

Check Tire

Pressure

Check Hydraulic

Return Filter

Indicator

Change Wheel

End Oil

Check Boom

Chain Tension

Air Filter

Restriction

Indicator

Check Auto-

Sway Function

Change Engine

Oil & Filter

Check Engine

Oil Level

Change

Transmission

Oil & Filter

Check Hydraulic

Oil Level

Change

Transfer

Case Oil

G10-55A & G12-55A AccuPlace

Drain Fuel/

Water

Separator

EVERY

Check Engine Coolant Level

Check

Battery

Lubrication

Schedule

MY1731

2.9

Page 20

General Information and Specifications

2.5.2 250, 500, 1000 & 1500 Hour

EVERY

250

Change Engine

Oil and

Filter*

Check Boom

Chain

Tension

Change Fuel

Filter

Check Axle

Oil Level

Check Boom

Bearing

Pads

(

Check Wheel

Lug Nut

Torque

)

Check Wheel

End Oil Levels

Check Transfer

Case Oil Level

EVERY

500

EVERY

1000

Air Filter

Vacuator

Valve

Check Rear Axle

Stabilization (if equipped)

Check

Fan Belt

Change

Transmission

Oil & Filter

Change

Transfer Case

Oil

Change Axle Oil

Change Wheel

End Oil

EVERY

1500

Change

Engine Coolant

Note: Engine oil & filter service interval can be extended. See Engine Manual for details.

2.10

Change

Hydraulic

Fluid & Filters

Change

Hydraulic Tank

Breather

MY0090

G10-55A & G12-55A AccuPlace

Page 21

2.6 LUBRICATION SCHEDULES

a. 50 Hour

EVERY

General Information and Specifications

G10-55A & G12-55A AccuPlace

OY1630

2.11

Page 22

General Information and Specifications

b. 250 Hour

EVERY

250

2.12

OW1210

G10-55A & G12-55A AccuPlace

Page 23

Section 3

Boom

Contents

PARAGRAPH TITLE PAGE

3.1 Boom System Component Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2

3.2 Boom System - Four Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.2.1 Boom System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.3 Boom Assembly Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.3.1 Boom Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3

3.3.2 Second, Third & Fourth Boom Section Removal . . . . . . . . . . . . . . . . . . . 3.4

3.3.3 Third & Fourth Boom Section Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4

3.3.4 Fourth Boom Section Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5

3.3.5 Fourth Boom Section Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5

3.3.6 Third & Fourth Boom Section Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3.6

3.3.7 Second Boom Section Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7

3.3.8 Boom Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8

3.4 Boom Extend and Retract Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9

3.4.1 Boom Chain Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9

3.4.2 Inspection Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9

3.4.3 Expose Chains for Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.11

3.4.4 Chain Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.12

3.4.5 Retract Chain Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.12

3.4.6 Retract Chain Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13

3.4.7 Extend Chain Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13

3.4.8 Extend Chain Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13

3.5 Boom Section Separation Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14

3.6 Hydraulic Sub-Assembly Removal/Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14

3.6.1 Hydraulic Sub-Assembly Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14

3.6.2 Assembling the Hydraulic Sub-Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 3.16

3.6.3 Hydraulic Sub-Assembly Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16

3.7 Boom Wear Pads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17

3.7.1 Wear Pad Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17

3.7.2 Boom Wear Pad Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17

3.7.3 Boom Wear Pad Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17

3.8 Quick Switch Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18

3.8.1 Quick Switch Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18

3.8.2 Quick Switch Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18

3.9 Forks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.18

3.10 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.19

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3.1 BOOM SYSTEM COMPONENT TERMINOLOGY

The following illustrations identify the components that are referred to throughout this section.

EXTEND

CHAINS

FOURTH BOOM

SECTION

ELECTRICAL

CONNECTION

THIRD BOOM

SECTION

SECOND BOOM

SECTION

FIRST

BOOM

SECTION

ATTACHMENT

QUICK SWITCH

ATTACHMENT

TILT CYLINDER

BOOM HYDRAULIC

ASSEMBLY

(Inside Boom)

(Underside Of Boom)

EXTEND/RETRACT

CYLINDER

RETRACT

CHAINS

HOSE

SHEAVES

MAP0500

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3.2 BOOM SYSTEM - FOUR SECTION

3.2.1 Boom System Operation

The four section boom consists of the first, second, third and fourth assemblies with double third and fourth section extend chains, a double third section retract chain and a single fourth section retract chain.

As the extend/retract cylinder, which is anchored at the front of the second boom section, and the rear of the first boom section begins to extend, it forces the second boom section out of the first boom section.

The boom sections are connected by extend and retract chains. These chains are routed around sheaves on the second and third boom sections. As the second section is forced out hydraulically, the third and fourth boom sections are pulled out by the extend chains.

As hydraulic pressure is applied to the retract port on the extend/retract cylinder, the second boom section is pulled back into the first boom section, and the retract chain pulls the third and fourth boom sections back into the second boom section.

This mechanical linkage formed by the chains and supporting hardware, extends and retracts the third and fourth boom sections at the same rate.

The boom section lifts and lowers via action of the lift/ lower cylinder.

3.3 BOOM ASSEMBLY MAINTENANCE

These instructions must be completed in sequence. The second, third and fourth boom sections are removed from the first boom section. The third and fourth boom sections are removed from the second boom section. The fourth boom section is removed from the third boom section.

Before beginning, conduct a visual inspection of the machine and work area, and review the task about to be undertaken. Read, understand and follow these instructions.

3.3.1 Boom Removal

1. Remove any attachment from the quick switch assembly.

Note: If replacing the fourth section boom, remove the quick switch from the fourth section. Refer to Section

3.8.1, “Quick Switch Removal.”

2. Park the machine on a hard, level surface, level the machine, fully retract the boom, raise the boom, place the transmission control lever in (N) NEUTRAL, engage the park brake and shut the engine OFF.

3. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

4. Open the engine cover. Allow the system fluids to cool.

5. Remove the battery negative (-) cable from the battery negative (-) terminal.

6. Support the front of the boom by placing a sling behind the boom head.

7. Label, disconnect and cap all hydraulic hoses for the extend/retract and tilt circuits. Cap all fittings and openings to keep dirt & debris from entering the hydraulic system.

8. Support the lift cylinder on the left side of the machine. Remove the lock bolt and rod end pin. Lower the lift cylinder onto the frame rails. Repeat this step for the right side lift cylinder.

9. Lower the boom to a level position and place a suitable support under the boom head. Reposition the slings to each end of the boom.

10. Remove the boom angle sensors from both the left and right side of the boom. Refer to Section 9.11.12, “Boom Angle Sensors.”

11. Remove the bolt securing the boom pivot pin. Pull out the boom pivot pin.

12. Lift the complete boom off machine and set on level ground or supports.

WARNING

NEVER weld or drill the boom unless approved in writing by JLG. The structural integrity of the boom will be impaired if subjected to any repair involving welding or drilling. Failure to comply can result in death or severe personal injury.

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Boom

3.3.2 Second, Third & Fourth Boom Section Removal

1. Set the complete boom on level ground and by repositioning the slings, turn boom over on to the top side. Set the complete boom on suitable stands to begin tear down.

Note: With the complete boom setting upside down, the removal and replacing of each boom section, hoses, extend and retract chains and hose carrier are made much easier.

2. Remove the extend/retract cylinder support from the front of the boom.

3. Support the extend/retract cylinder with a suitable sling. Remove the lock bolt and pin from both ends of the cylinder. Remove the cylinder.

4. Unhook the latch on the Boom Length Sensor cable from the third boom section. Refer to Section

9.11.13, “Boom Length Sensor.”

5. At the boom head, attach a sling through the rod end of the tilt cylinder. Remove both hoses from the tilt cylinder. Plug the hose ends and cap the tilt cylinder fittings to prevent dirt and debris from entering the hydraulic system. Remove the pin from the barrel end of the tilt cylinder and remove the cylinder from the boom head.

6. Loosen and remove the bottom rear wear pads and rear side bearing pads from the second boom section. Tag each pad, backing plate, shim and bolts from each location.

7. Release tension from the hoses on the hose take-up weldment (1).

hose ends and tube ends to prevent dirt and debris from entering the hydraulic system.

9. Disconnect the top front chains (3) from the chain clevis on the first and second boom section.

10. Release the chain tension from the front top chains.

11. Remove the front top chain rollers from the second and third boom sections.

12. Remove the chain adjustment block (4) from the first boom section.

13. Remove all wear pads from the front of the first boom section. Tag each pad, backing plate, shim and bolts from each location.

14. Carefully pull the second, third and fourth boom sections together from the first boom section and place on suitable support for further separation.

3.3.3 Third & Fourth Boom Section Removal

1. Loosen and remove the bottom rear and side wear pads from the third boom section. Tag each pad, backing plate, shim and bolts from each location.

2. Remove the standard and optional hose sheaves from the rear of the second boom section.

3. Remove the chain and chain clevis (5) from the rear of the second boom section.

MAP0660

8. Loosen the hydraulic hoses (2) and electrical cables if equipped on the hose take-up weldment. Plug the

3.4

MAP0670

4. Remove the hydraulic sub-assembly bracket (6) and hardware from the rear of the third boom section.

5. Pull the hydraulic sub-assembly partially out through the rear of the boom to access the hoses.

6. Loosen and remove the hoses from the rear of the hydraulic sub-assembly.

7. Release the tension on the clevis before proceeding.

8. Loosen and remove the chain adjustment block from the bottom of the boom.

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9. Loosen and remove all the wear pads from the front of the second boom section. Tag each pad, backing plate, shim and bolts from each location.

10. Place a sling around the third boom section, lift and slowly pull the third and fourth boom sections (7) approximately half way out of the second boom section. Lower the third and fourth boom sections onto a suitable support.

11. Relocate the sling or using two slings for better stability, balance the two boom sections and slowly pull them out of the second boom section being careful not to damage any surrounding components.

MY1690

12. Remove the chain (8) from the second boom section to the third boom section after the boom sections are free from each other.

13. Lower the third and fourth boom sections onto a suitable support.

3.3.4 Fourth Boom Section Removal

1. Remove the bottom rear and side bearing pads from the fourth boom section. Tag each pad, backing plate, shim and bolts from each location.

2. Loosen and remove the 3/4 in. chain (9) through the rear of the fourth boom section.

4. Loosen and remove the front wear pads and supports from the third boom section. Tag each pad, backing plate, shim and bolts from each location.

5. Carefully pull the fourth boom section out of the third boom section, taking care to protect the chains.

6. Disconnect the chains when the boom sections are free from each other.

7. Place the fourth boom section onto suitable supports.

If the hydraulic sub-assembly (11) is going to be removed:

MX0390

8. Remove the guide bracket from the front of the hydraulic sub-assembly.

9. Remove the hardware securing the hydraulic subassembly to the front of the boom.

10. Install a sling on the hydraulic sub-assembly at the rear of the boom. Slowly pull it loose from the bottom bracket located on the bottom plate of the fourth boom section.

11. When the sub-assembly is approximately 25% free of the boom, fasten the two hose carriers together (using nylon tie-wraps or nylon straps) to prevent them from separating.

Note: Do not wrap the hose carrier since it will not prevent the two hydraulic carriers from moving apart sideways.

12. Continue to withdraw the sub-assembly, fastening the hydraulic carriers together as they are removed.

13. When the hydraulic carrier is approximately 75% tied together, pull the assembly free of the boom.

3.3.5 Fourth Boom Section Installation

MX0380

3. Loosen and remove the retract chain roller (10) at the rear of the third boom section.

G10-55A & G12-55A AccuPlace

1. Clean and lubricate the inside of the boom sections where the hydraulic sub-assembly rides (if removed).

2. Using a sling, lift the balanced hydraulic subassembly and slowly insert it into the fourth boom section.

3. As the first tie wrap nears the boom, remove the tie wrap and continue inserting the sub-assembly and removing each tie wrap until the sub-assembly is fully inserted.

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Boom

Note: Be certain the hydraulic sub-assembly locks into place on the pin bracket at the bottom of the fourth boom section.

4. Reconnect the hydraulic hoses and any optional circuits.

5. Install the guide bracket and hardware to secure the hydraulic sub-assembly to the front of the boom.

6. Reinstall the hose take-up compression spring. Torque the jam nut to 100 lb-ft. There should be a 1 in. (25 mm) gap from the back of the jam nut to the end of the threads on the hose take-up weldment.

7. Install the wear pads, backing plates and shims to the top, bottom and sides of the fourth boom section. Do not shim or tighten the bolts at this time.

8. Attach the chain clevis and the keeper plate to the inside rear of the boom.

9. Install the grease fitting extensions for the bottom rear wear pads.

10. Lubricate the extend chain completely. Make sure the chain is inspected and is in good working condition. See Section 3.4.4, “Chain Lubrication.”

11. Attach the chain to the chain clevis.

12. Attach the chain clevis to the top of the fourth boom section.

13. Grease the inside of the third boom section on areas where the fourth boom section wear pads will slide.

14. Using a suitable sling, balance the fourth boom section and carefully slide 3-4 ft (1-1,5 m) into the front of the third boom section. Set the fourth boom section head onto suitable supports and reset sling under the boom head. Carefully slide the fourth boom section into the third boom section. Leave 6-8 in (15-20 cm) of the fourth boom section out to be able to install wear pads on the front of the third boom section.

15. With the boom head still supported, install the top wear pads, washers and bolts in the front of the third boom section. Remove the boom head from supports and install the remaining wear pads inside the third boom section. Do not shim or tighten the bolts at this time.

16. Install the grease fittings for the wear pad and chain roller assembly.

3.3.6 Third & Fourth Boom Section

Installation

1. Install the top, bottom and side rear wear pads onto the third boom section. Do not shim or tighten the bolts at this time.

2. Grease the inside of the second boom section on areas where the third section wear pads will slide.

3. Install the grease fittings for the wear pad and chain roller assembly.

4. Install the chain clevis to the rear of the third boom section.

5. Install the chain roller (1) at the bottom rear of the boom.

6. Install the chain roller at the top front of the boom.

7. Lay out and lubricate the retract chain. Make sure the chain has been inspected and meets the adjustment parameters in Section 3.4.1, “Boom Chain Inspection.”

8. Connect the retract chain (2) to the clevis at the rear of the fourth boom section.

MX0380

9. Connect the chain to the chain clevis and the clevis to the chain adjustment block. Adjust the nut until the gap between the nut and the washer is 1/8 in. (3,175 mm). Torque the locknut to 100 lb-ft (135 Nm).

10. Lay out and lubricate the two extend chains. Make sure the chains have been inspected and meets the adjustment parameters in Section 3.4.1, “Boom Chain Inspection.”

11. Attach the rear chain clevis to the chain.

12. Using a suitable sling, balance the fourth and third boom sections and carefully slide 3-4 ft (1-1,5 m) into the front of the second boom section. Set the fourth and third boom sections onto suitable supports and reset the sling under the boom head. Carefully slide the fourth and third boom sections into the second boom section. Leave 6-8 in (15-20 cm) of the third boom section out to be able to install the wear pads on the front of the second section.

13. With the boom still supported, install the top wear pads in the front of the second boom section.

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Remove the boom from supports and install the remaining wear pads to the second boom section. Do not shim or tighten bolts at this time.

14. Install the grease fittings for the wear pad and chain roller assembly.

3.3.7 Second Boom Section Installation

1. Install the top, bottom and side rear wear pads onto the second boom section. Do not shim or tighten the bolts and this time.

2. Lubricate the inside of the first boom section on areas where the second boom section wear pads will slide.

3. Attach the chain clevis (3) to the rear of the third boom section.

4. Using a suitable sling, balance the second, third and fourth boom sections and carefully slide 3-4 ft into the front of the first boom section. Set the second, third and fourth boom sections on a suitable support and reset the sling under the boom head of the fourth boom section. Carefully slide the three boom sections into the first boom section. Leave 6-8 in of the two boom sections out to be able to install the wear pad block and the wear pads in the front of the first boom section.

5. Install the chain adjustment block (4) to the bottom of the boom.

MX0440

6. With the boom still supported, install the top wear pads in the front of the first boom section. Remove the boom from supports and install the remaining wear pads to the first boom section. Do not shim or tighten bolts at this time.

7. Lubricate the retract chain on the bottom of the second boom section.

8. Install the lube fittings to the wear pad and chain roller assembly.

9. Connect the chain clevis (5) to the second boom section.

10. Assemble the rear bottom chain roller to the second boom section.

11. Shim all wear pads needed to obtain the minimum gap of 1/16 in (1,6 mm). Tighten all wear pad bolts to the correct values. Refer to Section 3.7, “Boom Wear Pads.”

12. Install the hose sheave to the second boom section.

13. Attach the hoses, and optional auxiliary hoses and electrical cable to the hose carrier at the rear of the boom.

14. At the rear of the boom, install the bracket (6) to the back of the hose carrier.

MAP0670

15. Install the hose guide bracket for the electric and hydraulic options at the rear of the boom.

16. Attach the chain clevis to the chain.

17. Install the hoses to the hose carrier at the rear of the boom.

18. Install the hose guide bracket to the rear of the second boom section.

19. Install the optional hydraulics and electrical cables if equipped.

20. Connect the hose assembly to the take-up weldment.

MY1720

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21. Install the top front chain roller (7) to the second and third boom sections.

MAP0740

22. Install the cushion clamps around the hoses on the first boom section.

23. Connect the top front chain clevises to the chains, then connect the chains to the first and second boom sections.

24. Adjust the retract chain (8) at the bottom front of the first boom section to 2 7/8 in. (73 mm) for the initial setup.

25. Install the auxiliary hydraulic hoses and electrical cables to the boomhead of the fourth boom section.

26. Using a suitable sling, install the tilt cylinder to the front of the boom.

27. Using a suitable sling, install the extend/retract cylinder and support to the second and first boom section.

28. Reconnect the latch on the Boom Length Sensor cable to the third boom section. Refer to Section

9.11.13, “Boom Length Sensor.”

3.3.8 Boom Installation

1. Park the machine on a hard, level surface, place the transmission control lever in (N) NEUTRAL, engage the park brake, chock the wheels and shut the engine OFF.

2. Using suitable slings, balance the boom assembly, lift and carefully guide the boom into place. Align the frame pivot bore with the boom assembly pivot bore. Install the boom pivot pin.

3. With the sling still in place, install the compensation cylinder, pins and bolts.

4. With the sling still in place, install the rod end of the left lift/lower cylinder, pin and lock bolt. Repeat for the right side lift/lower cylinder.

Note: Raising the boom up or down with the sling may be necessary so the boom, compensation and lift/lower cylinder bores can be aligned for easier pin installation.

Note: Grease the boom pivot bore, compensation cylinder rod ends, lift/lower cylinder rod end and pins before installing.

5. Uncap and reconnect the previously labeled hydraulic hoses to the extend/retract cylinder.

6. Uncap and connect any remaining hydraulic fittings to their appropriate locations.

7. Recheck the wear pad gaps to ensure they meet the minimum gap requirement. Shim if necessary.

8. Ensure that the boom chains are properly adjusted. Refer to Section 3.5, “Boom Section Separation Adjustment.”

9. Install and reconnect the boom angle sensors to both the left and right side of the boom. Refer to Section 9.11.12, “Boom Angle Sensors.”

10. Connect the battery negative (-) cable to the battery negative (-) terminal.

11. Start the engine and operate all boom functions several times. Check for leaks, and check the hydraulic fluid level in the reservoir; add fluid if required.

12. Clean up all debris, hydraulic fluid, etc., in, on, near and around the machine.

13. Close and secure the engine cover.

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3.4 BOOM EXTEND AND RETRACT

CHAINS

3.4.1 Boom Chain Inspection

WARNING

Worn pins, stretched or cracked links or corrosive environments can cause chain failure. A chain failure could result in uncontrolled boom movement, loss of load or machine instability, and could cause death or serious injury and/or property damage.

Under normal operating conditions the boom chains will need to be inspected every 250 hours of operation. The retract chains need to be exposed and inspected every 1000 hours of operation. Environmental conditions and dynamic impulse/shock loads can drastically affect normal operating conditions and require more frequent inspection intervals.

Environments in which material handling vehicles operate can vary widely from outdoor moisture to temperature to mildly corrosive or highly corrosive industrial atmospheres, in addition to abrasive exposures such as sand and grit. Some effects can be as follows:

• Moisture - Corrosive rusting reduces chain strength by pitting and cracking.

• Temperature - Low temperature reduces chain strength by embrittlement. Going in and out of cold storage results in moisture from condensation.

• Chemical Solutions or Vapors - Corrosive attack on the chain components and/or the mechanical connections between the chain components. Cracking can be (and often is) microscopic. Going from microscopic cracking to complete failure can be either abrupt or may require an extended period of time.

Following are some examples of dynamic shock loading which can impose abnormal loads above the endurance limit of a leaf chain.

• High velocity movement of load, followed by sudden, abrupt stops.

• Carrying loads in suspension over irregular surfaces such as railroad tracks, potholes, and rough terrain.

• Attempting to “inch” loads which are beyond the rated capacity of the vehicle.

The above load cycles and environmental conditions make it impossible to predict chain life. It is therefore necessary to conduct frequent inspections until replacement life can be predicted.

The boom chain’s normal life expectancy can be expressed as a maximum percent of elongation. This is generally 3%. As the chain flexes back and forth over the sheave, the bearing joints (pins and inside link plates) gradually incur wear due to ar ticulation.

3.4.2 Inspection Guidelines

1. Park the machine on a firm, level surface, raise the boom to a horizontal (level) position, place the transmission control lever in (N) NEUTRAL, engage the park brake switch.

2. Fully extend the boom until the extend chain is taut. Shut the engine off.

3. The extend chains will be visible for inspection with the vehicle in this state.

4. While doing the chain inspection, check all chain clevis ends for distortion or cracking and sheaves for bearing wear or grooving from the chain.

5. Inspect the retract chains every 1000 hours of operation.

6. Inspect the chains for the following conditions:

• Abrasives - Accelerated wearing and scoring of the articulating members of the chain (pins and plates), with a corresponding reduction in chain strength. Due to the inaccessibility of the bearing surfaces (pin surfaces and plate apertures), wear and scoring are not readily noticeable to the naked eye.

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Edge Wear

Check the chain for wear on the link plate edges caused by running back and forth over the sheave. The maximum reduction of material should not exceed 5%. Measure and compare to a normal link plate height by measuring a portion of chain that does not run over the sheave. If the measured plate height (1) is 5% less than the normal plate height (2), discard and replace the chain.

Elongation

It is important to measure the chain in the section that moves over the sheaves because it receives the most frequent articulation. Measuring the chain near its clevis terminals could give an inaccurate reading. The ends of the chains, near the clevis terminal, will not have flexed as frequently, if at all, as the middle of the chains.

It is best to measure in 12 pin increments from pin center to pin center. For example, if the links are one inch from pin center to pin center, the distance should be 12 in (305 mm). If the links are 3/4 in apart, the distance after 12 pins should be 9 in.

If the distance measured (3) is 3% greater than the normal length (4), discard and replace the chain.

MZ1463

Distorted or Battered Link Plates

Distorted or battered link plates (5) on a leaf chain can cause tight joints and prevent flexing.

MZ1466

Turning or Protruding Pins

Highly loaded chain, operating with inadequate lubrication can generate abnormal frictional forces between pin and link plates. When chain is allowed to operate in this condition, a pin or series of pins, can begin to twist out of a chain, resulting in failure.

Examine the pin head rivets to determine if the “VEE” flats are still in correct alignment (6). Chain with rotated/displaced heads (7) or abnormal pin protrusion (8) should be replaced immediately.

DO NOT attempt to repair the chain by welding or driving the pin(s) back into the chain. Once the press fit integrity between outside plates and pins has been altered, it cannot be restored.

Any wear pattern on the pin heads or the sides of the link plates indicates misalignment in the system. This condition damages the chain as well as increases frictional loading and should be corrected.

3.10

MZ1465

MY1360

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Cracked Plates

Inspect the chains very carefully, front and back as well as side to side, for any evidence of cracked plates. If any one crack is discovered, the chain should be replaced in its entirety.

It is important, however to determine the cause of the crack before installing a new chain so the condition does not repeat itself.

The types of cracks are:

• Fatigue Cracking -

Fatigue cracks (9) are a result of repeated cyclic loading beyond

MZ1467

the chain’s endurance limit.

• Stress Corrosion

Cracking - The

outside link plates

are particularly susceptible to stress corrosion cracking (10).

• Corrosion Fatigue Cracking - Corrosion

fatigue cracks are very similar to fatigue cracks in appearance. Corrosion fatigue is the combined action of an aggressive environment and cyclic stress.

Other Modes of Failure

• Ultimate Strength Failure -

These types of failures are caused by overloads far in

excess of the design load. Either fractured plates (1) or

enlarged holes (2) can occur. If either of these failures occurs, the chain should be replaced immediately.

MZ1468

MZ1469

MZ1470

3.4.3 Expose Chains for Inspection

c. Extend Chains

1. Park the machine on a firm, level surface. Place the transmission control lever in (N) NEUTRAL, engage the park brake switch and raise the boom to a horizontal (level) position.

2. Fully extend the boom until both extend chains are taut. Shut the engine OFF.

The extend chains will be visible for inspection with the machine in this state.

While doing the chain inspection, check all chain clevis ends for distortion or cracking and sheaves for bearing wear or grooving from the chain.

If during the inspection, any chain is found to be damaged or stretched, the chain must recommended that when any chain is replaced, that all the chains and clevises be replaced at the same time.

d. Retract Chains

The three retract chains are only partially visible through the rear of the boom with all the sections retracted. It is possible to see a section of the retract chain as the boom is slowly extended. If there is ANY question that one or all the retract chains are damaged, the boom should be removed and disassembled with the retract chains being inspected and replaced if necessary.

Note: DO NOT attempt to repair a chain. Replace a stretched or damaged chain with a new part. Always replace both the chain and the clevis. It is recommended that when any chain is replaced, that all chains and clevis’ be replaced at the same time.

be replaced. It is

• Tight Joints

- All joints in the chain should flex freely. Tight joints (3)

resist flexing. If the problem is caused by dirt or foreign substance packed in the joints, clean and lubricate thoroughly before re-installing the chain. If the problem is caused by corrosion and rust or bent pins, replace the chain.

G10-55A & G12-55A AccuPlace

MZ1471

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3.4.4 Chain Lubrication

After inspection and before being returned to service, chains must be lubricated with a quality chain lubricant (“LUBRIPLATE” Chain & Cable Fluid, “LPS3” or equivalent).

The lubricant must penetrate the chain joint to prevent wear. Applying lubricant to the external surfaces will prevent rust, but the chains should be articulated to make sure the lubricant penetrates to the working surfaces between the pins and links.

To prepare the chain for lubrication, the chain plates should be brushed with a stiff brush or wire brush to clear the space between the plates so that lubricant can penetrate to the working surfaces.

Lubricant may be applied with a narrow paint brush or directly poured on, but the chain should be well flooded with lubricant and the boom should be extended and retracted to be sure that the lubricant penetrates to the working surfaces. All surplus lubricant should be wiped away from the external surfaces. DO NOT use a solvent for this wiping operation.

Regular application of lubricant is necessary to make sure that all working surfaces are adequately lubricated. In extremely dusty conditions, it may be necessary to lubricate the chains more often.

Lubrication of chains on vehicles working consistently in extreme hot or cold conditions requires special consideration. It is important that a reputable lubrication specialist, a JLG Distributor or the vehicle distributor be consulted for guidance.

3.4.5 Retract Chain Removal

The following section explains the removal of the retract chains without removing the boom assemblies.

Note: The retract chain on the bottom of the boom must be removed to gain access to the inner retract chain.

To remove the 1 in. retract chain from the third to first boom sections:

1. Park the machine on level ground. Place the transmission control lever in (N) NEUTRAL, engage the parking brake switch, level the boom and shut the engine OFF.

2. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

3. Remove the battery negative (-) cable from the battery negative (-) terminal.

4. Attach a suitable sling to the extend/retract cylinder. Remove the extend/retract cylinder support.

5. Remove the rod end pin and lower the cylinder onto the frame rails. Lowering the extend/retract cylinder will allow access to the chains.

6. Remove tension from the chain by backing off the jam nut and adjusting nut (1).

MX0510

7. Remove the four bolts (2) from the chain adjustment block.

8. Remove the chain from the clevis (3) at the block.

9. Install a nylon tie wrap through the holes of the removed chain, making a loop with a tie wrap and tie a rope to the loop.

10. At the rear of the boom, pull the chain to the rear to allow slack for removal.

11. Remove the chain from the clevis and drop it free from the boom.

12. Holding a rope at the front adjustment block, carefully pull the chain out through the back of the boom.

13. Untie the rope and leave it in place for reinstallation of the chain.

To remove the 3/4 in. retract chain from the fourth to second boom sections:

1. Remove the jam nut (4) from the chain clevis installed in the chain adjustment block.

2. Back off the adjusting nut fully on the chain clevis. Do not remove the nut from the clevis.

3. Remove the chain from the clevis, install a nylon tiewrap through the holes in the chain, making a loop with the tie-wrap and tie a rope to the loop.

4. Move to the back of the boom and pull the chain to the rear to allow slack for removal.

5. Remove the chain from the clevis and drop it free from the boom.

6. Holding the rope at the front, carefully pull the chain out through the back of the boom until it’s free.

7. Untie the rope and leave it in place for reinstallation of the chain.

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Boom

3.4.6 Retract Chain Installation

Inspect and lubricate chains thoroughly before installation. Articulate the chains to make sure all working surfaces are thoroughly lubricated.

Note: If the inner retract chain was removed, it must be installed first.

1. Fasten a rope to the end of the 3/4 in. chain in order to pull it back into the boom.

2. Attach the chain to the chain clevis at the rear of the boom.

3. Carefully pull the chain into the boom until it can be fastened to the chain clevis.

4. Remove the rope.

5. Fasten the chain into the clevis by installing the pin and retaining ring.

6. Apply Loctite

242 to the jam nut threads and torque

to 100 lb-ft (135 Nm).

To install the outer retract chain:

1. Fasten a rope to the end of the chain in order to pull it back into the boom.

2. Attach the chain to the chain clevis at the rear of the boom.

3. Carefully pull the chain into the boom until it can be fastened to the chain clevis.

4. Remove the rope.

5. Fastened the chain into the clevis by installing the pin and cotter pin.

6. Install the chain adjustment block and mounting bolts. Torque the chain adjustment block mounting bolts to 360-390 lb-ft (475-530 Nm).

7. Install the extend/retract cylinder and cylinder support.

8. Adjust the retract chains as needed. Refer to Section

3.5, “Boom Section Separation Adjustment.”

9. Connect the battery negative (-) cable to the battery negative (-) terminal.

3.4.7 Extend Chain Removal

The following section explains the removal of the extend chains without removing the boom assemblies.

1. Park the machine on level ground. Place the transmission control lever in (N) NEUTRAL, engage the parking brake switch, level the boom, extend the boom far enough to access the chain anchor and the clevis through the top rear access hole, shut the engine OFF.

2. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

3. Remove the battery negative (-) cable from the battery negative (-) terminal.

4. Secure the boom sections together to prevent uncontrolled boom run out when the extend chains are removed.

5. On the chain being removed, loosen and remove the jam nut from the rear chain clevis and back off the adjusting nut on the chain clevis to the end of the threads. Do not completely remove the nut.

6. Remove the chain clevis pin and retaining ring to free the chain.

7. Install the nylon tie wrap through the holes in the chain, making a loop with the tie wrap and tie a rope to the loop.

8. Pull the slack to the chain clevis at the front of the boom.

9. Remove the clevis pin and the retaining ring from the chain and chain clevis.

10. Install a nylon tie wrap through the chain holes, forming a loop and tie a rope to the loop.

11. Carefully pull the chain out of the boom.

12. Untie the rope and leave it in place for reinstallation of the chain.

3.4.8 Extend Chain Installation

The following section explains the installation of the retract chains without removing the boom assemblies.

Inspect and lubricate chains thoroughly before installation.

1. Fasten the previously used rope to the end of the extend chain.

2. Carefully pull the chain into the boom to the chain clevis anchor.

3. Fasten the chain to clevis with a pin and cotter pin.

4. At the other end of the chain, connect the chain to the clevis fastening the chain to the clevis with a pin and retaining ring.

5. Install the chain clevis fastening and adjusting hardware on both ends.

6. Remove any clamping devises being used to keep the boom sections from moving.

7. Adjust the extend chains as needed. Refer to Section 3.5, “Boom Section Separation Adjustment.”

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Boom

3.5 BOOM SECTION SEPARATION ADJUSTMENT

1. Park the machine on level ground. Place the transmission control lever in (N) NEUTRAL, engage the parking brake switch and raise the boom to a horizontal (level) position.

2. Extend the boom 4 ft to 5 ft, then fully retract the boom.

3. Measure the gap between the flat washer at the extend chain anchor on the top front of the first boom section and the second boom section. If the gap is greater that 3/8 in. (9.52 mm), the boom chains will need to be adjusted.

While doing the chain inspection, check all chain clevis ends for distortion or cracking and sheaves for bearing wear or grooving from the chain.

4. If during the inspection, any chain is found to be damaged or stretched, the chain must is recommended that when any chain is replaced, that all the chains and clevises same time.

Adjust the extend chain as follows:

1. Loosen the lock nut on each of the extend chains.

2. Tighten the adjusting nut on the first boom section until the gap between the flat washers and boom is 3/8 in. (9,52 mm) maximum. The gap must be equal on both chains. Torque the lock nut to 100 lb-ft (135 Nm).

3. Tighten the adjusting nut on the second boom section until the gap between the washer and boom is 3/8 in. (9,52 mm) maximum. Torque the lock nut to 100 lb-ft (135 Nm).

4. After adjusting, check to see that the boom sections and access holes are aligned. If they are not, the retract chain will need to be adjusted as well.

Adjust the retract chain as follows:

1. Fully retract the boom.

2. Measure the distance between the second boom section and the third boom section (1). The dimension should be 0.500 in, + 0.250 in - 0.0 in (12,7 mm, + 6,75 mm - 0.0 mm).

be replaced. It

be replaced at the

MY1320

3. Loosen the retract chain lock nut and adjusting nut as far as possible.

4. Tighten the retract chain adjusting nut until the proper distance is obtained and proper access hole alignment is obtained.

5. Torque the lock nut to 100 lb-ft (135 Nm).

6. Recheck the extend chain adjustments and readjust if necessary.

7. Measure the distance between the third boom section and fourth boom section (2). The dimension should be 18.5 in, + 0.25 in - 0.0 in (469,9 mm, + 6,75 mm - 0,0 mm)

8. Tighten the retract chain adjusting nut until the proper distance is obtained and proper access hole alignment is obtained.

9. Torque the lock nuts to 100 lb-ft (135 Nm).

10. Re-adjust the extend chain as needed.

3.6 HYDRAULIC SUB-ASSEMBLY REMOVAL/INSTALLATION

The hydraulic sub-assembly is located primarily in the fourth boom section. It is fastened at the bottom front of the fourth boom section and at the rear of the third boom section.

3.6.1 Hydraulic Sub-Assembly Removal

1. Remove any attachment from the quick switch assembly.

Note: Allow adequate room in front of the machine when removing and installing the hydraulic subassembly.

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Boom

2. Park the machine on a hard, level surface, level the machine, fully retract the boom, level the boom, place the transmission control lever in (N) NEUTRAL, engage the park brake and shut the engine OFF.

3. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

4. Open the engine cover. Allow the system fluids to cool.

5. Remove the battery negative (-) cable from the battery negative (-) terminal.

6. Label and disconnect the tilt and auxiliary hydraulic hoses attached to the sub-assembly at the rear of the boom and at the front of the boom head. Plug and cap the hose ends to prevent dirt and debris from entering the hydraulic system.

7. If equipped, label and disconnect any electrical connections at the front and rear of the boom assembly.

Note: Tag or identify each hose to the corresponding fitting it was removed from.

10. Loosen and remove the sub-assembly bracket (4) at the rear of the third boom section.

MY2720

11. Install a sling around the sub-assembly at the front of the boom. With a suitable lifting device, slowly pull the sub-assembly loose from the bottom bracket (5) located approximately halfway in the fourth boom section.

FRONT

8. Loosen and remove both cap screws and locknuts (2) from the sub-assembly bracket at the front of the fourth boom section.

MY2710

9. Loosen and remove the guide bracket (3) from the front of the fourth boom section.

MY2700

12. When the sub-assembly is pulled approximately 25% out of the boom, fasten the two hydraulic carriers together using plastic tie wraps or nylon straps to keep them from separating.

Note: Do Not wrap the hose carrier since it will not prevent the two hydraulic carriers from moving apart sideways.

13. Continue withdrawing the sub-assembly, fastening the two hydraulic carriers together.

14. With the two hose carriers tied together, remove the sub-assembly and set on the ground or proper supports.

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Boom

3.6.2 Assembling the Hydraulic SubAssembly

The following procedure is described with the assumption that all components have been removed and assembly proceeding from the beginning.

MY2730

1. Place both sections on a suitable stand or support.

2. Install the wear pad to the bottom of the upper hydraulic carrier.

3. Install the bulkhead fittings to each hydraulic carrier.

4. Install the tube assemblies to the bulkhead fittings on each hydraulic carrier.

5. Install the cushion clamps to the tube assemblies and secure to each hydraulic carrier.

6. Install the hose carrier to each hydraulic carrier and install each tilt hose and auxiliary hose to the proper fitting or tube connection.

7. Tie wrap the hydraulic hoses together where they extend from each end of the hose carrier.

8. Fasten the two hydraulic carriers together using plastic tie wraps or nylon straps for stability.

3.6.3 Hydraulic Sub-Assembly Installation

1. Clean and lubricate the side surfaces where the hydraulic sub-assembly rides.

2. Install the guide bracket (1) on the front of the hydraulic sub-assembly.

3. Fully collapse the hose carriers and secure together using plastic tie wraps or nylon straps to keep them from separating.

4. Install a sling around the balance point of the subassembly. With a suitable lifting device, slowly insert the sub-assembly into the front of the fourth boom section.

5. Remove the first plastic tie wrap or nylon strap as the hydraulic sub-assembly is being inserted into the front of the fourth boom section.

6. Continue inserting the hydraulic sub-assembly and removing the plastic tie wraps or nylon straps until the sub-assembly is fully inserted into the boom.

7. Verify that the bottom bracket (2) on the subassembly is in place on the bottom plate (3) of the fourth boom section.

FRONT

MY2700

8. Install the cap screws, washers and nuts to the subassembly bracket at the rear of the third boom section.

9. Install both cap screws and locknuts to the subassembly bracket at the front of the fourth boom section.

10. Uncap and reconnect the previously labeled tilt and auxiliary hydraulic hoses to the proper fittings at the rear of the hydraulic sub-assembly.

11. Uncap and reconnect the previously labeled tilt and auxiliary hydraulic hoses to the proper fittings at the front of the fourth boom section.

12. If equipped, reconnect any electrical connections at the front and rear of the boom assembly.

3.16

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3.7 BOOM WEAR PADS

The wear pads on this machine are flat rectangular wear pads with metal inserts.

A total of 42 wear pads are installed on the boom.

3.7.1 Wear Pad Inspection

Inspect all wear pads for wear. If the angle indicators (3) on the ends of the wear pads are visible, the wear pads can be reused. If the pads show uneven wear (front to back), they should be replaced. Replace pads as a set if worn or damaged.

Boom

Ma2070

3.7.2 Boom Wear Pad Replacement

When replacing a wear pad on the boom, replace both wear pads on that side of the boom; e.g.: replace top front left and top front right wear pads at the same time.

Usually, shimming will remain the same when installing new wear pads. Some wear pads are secured to the boom using different bolts and washers. Keep bolts and washers with the same wear pad that is being replaced. When installing new wear pads, apply Loctite wear pad mounting bolts and torque to required specifications.

Wear pad bolt torques are:

3/8 in. bolt: 32-37 lb-ft (43-50 Nm)

1/2 in. bolt: 76-86 lb-ft (103-117 Nm)

Hollow 3/8 in. bolt: 15-17 lb-ft (20-23 Nm)

Hollow 1/2 in. bolt: 45-50 lb-ft (61-68 Nm)

242 to all

MY0630

3.7.3 Boom Wear Pad Lubrication

Note: The first shim next to a wear pad always needs to have the two hole configuration. The remaining pads (4) may have the large slot configuration.

Use shims under the wear pads as required to maintain a maximum gap of 1/16 in (1,6 mm) (5) between the wear pad on the front and sides of the boom. The gap at the rear of the boom should be no more than 3 mm (0.12”).

Shims are available in a 0.06 in (1,5 mm) thickness.

G10-55A & G12-55A AccuPlace

The boom has been factory lubricated for proper wear pad break-in and will normally require minor further lubrication. However, after replacing any wear pad(s), or after prolonged periods of inoperation, light lubrication of the boom wear surfaces with a factory authorized grease is recommended to keep the boom wear surfaces lubricated properly. Light lubrication of the boom wear surfaces is also recommended when the machine is stored, to help prevent rusting.

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Boom

3.8 QUICK SWITCH ASSEMBLY

3.8.1 Quick Switch Removal

1. Remove the lock bolt holding the tilt cylinder rod end pin to the quick switch assembly. Remove the Tilt Cylinder pin.

2. Support the quick switch assembly.Remove the capscrew and locknut securing the head pin to the boom head.

3. Inspect the above pins for nicks or surface corrosion. Use fine emery cloth to fix minor nicks or corrosion. If damaged or if it cannot be repaired, the pin must be replaced.

3.8.2 Quick Switch Installation

1. Assemble the quick switch to the boom head. Line up the quick switch between the mounts on the boom head. The quick switch should be centered in the boom head.

2. Coat the quick switch head pin with an anti-seize compound. Insert the quick switch head pin through the quick switch and boom head. Secure with the previous capscrew and locknut.

Align the quick switch with the tilt cylinder rod end and insert the tilt cylinder pin. Align the tilt cylinder pin and screw in the locking bolt. Torque as required.

3.9 FORKS

Forks should be cleaned and inspected prior to being attached to carriage. If the following criteria is not met, forks must be removed from service immediately.

Daily Inspection

1. Inspect forks (6) for cracks, paying special attention to heel (7) and mounting tubes (8).

2. Inspect forks for broken or bent tips (9) and twisted blades (10) and shanks (11).

Yearly Inspection

1. Straightness of the upper face of blade (10) and the front face of shank (11) should not exceed 0.5 percent of the length of blade or height of shank.

2. Angle (12) between upper face of blade and front face of shank should not exceed 93 degrees.

3. Thickness of blade (15) and shank (16) should not be reduced to 90 percent of original thickness.

4. Ensure fork length (14) is adequate for intended loads.

5. Fork markings should be legible, re-stamp if required.

6. Compare fork tips (13) when mounted on a carriage. Maximum difference in height of fork tips is 3 percent of the length of the blade (15).

MH6460

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3.10 TROUBLESHOOTING

This section provides an easy reference guide covering the most common problems that occur during operation of the boom.

Problem Cause Remedy

Boom

1. Boom will not extend or retract.

2. Boom shifts to right or left when extending.

3. Excessive boom pivot pin noise and/or wear.

1. Broken hydraulic hose(s) or tube(s) and/or connections leaking.

2. Extend/retract hydraulic system not operating properly.

3. Faulty extend/retract cylinder. 3. Repair cylinder. Refer to Section

4. Electronic control function not operating properly.

1. Boom side wear pads improperly shimmed or worn.

1. Insufficient lubrication. 1. Lubricate at regular intervals.

2. Worn bearing(s). 2. Replace bearing(s) and

1. Locate break, replace hose(s) or tube(s), tighten connections.

2. Refer to Section 8.4, “Hydraulic Circuits.”

8.10.1, “General Cylinder Removal Instructions.”

4. Check for DTC. Refer to Section

9.15.8, “Diagnostic Trouble Code (DTC) Table.”

1. Shim wear pads to correct gap. Replace wear pads as needed. Refer to Section 3.7.2, “Boom Wear Pad Replacement.”

Refer to Section 2.6, “Lubrication Schedules.” Replace worn pins as needed.

lubricate at regular intervals. Refer to Section 2.6, “Lubrication Schedules.”

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Boom

Problem Cause Remedy

4. Drooping chain, or jerky boom extend or retract functions.

1. Chain(s) tension not properly adjusted.

2. Chain(s) stretched or binding. 2. Replace chains as needed.

3. Wear pads loose, contaminated, excessively worn or damaged.

4. Contaminated, corroded or rusted wear pad sliding surfaces.

5. Extend/Retract hydraulic system not operating properly.

6. Damaged boom section. 6. Replace the damaged boom

7. Electronic control function not operating properly.

1. Adjust chain(s).

Refer to Section 3.5, “Boom Section Separation Adjustment.”

3. Replace wear pad. Refer to Section 3.7.2, “Boom Wear Pad Replacement.”

4. Remove contamination and/or corrosion from wear pad sliding surfaces and lubricate. If the surfaces cannot be reconditioned, replace the boom section(s).

5. Refer to Section 8.4, “Hydraulic Circuits.”

section. Refer to Section 3.3, “Boom Assembly Maintenance.”

7. Check for DTC. Refer to Section

9.15.8, “Diagnostic Trouble Code (DTC) Table.”

5. Boom will not raise or lower. 1. Broken hydraulic hoses or tubes and/or connection leaks.

2. Lift/lower hydraulic system not operating properly.

3. Faulty lift/lower cylinder. 3. Repair cylinder. Refer to Section

4. Seized boom pivot pin bearing. 4. Replace bearing.

5. Electronic control function not operating properly.

6. Excessive Lift/Lower cylinder pivot pin noise and/or wear.

1. Insufficient lubrication. 1. Lubricate at regular intervals.

2. Worn self-aligning bushing(s). 2. Replace bushing(s) and

1. Locate break, replace hose(s) or tube(s), tighten connections.

2. Refer to Section 8.4, “Hydraulic Circuits.”

8.10.1, “General Cylinder Removal Instructions.”

5. Check for DTC. Refer to Section

9.15.8, “Diagnostic Trouble Code (DTC) Table.”

Refer to Section 2.5, “Service and Maintenance Schedules.” Replace worn pins as needed.

lubricate at regular intervals. Refer to Section 2.6, “Lubrication Schedules.”

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Boom

Problem Cause Remedy

7. Rapid boom pad wear. 1. Incorrect wear pad gap. 1. Check wear pad gaps and

correct as needed. Refer to Section 3.7.2, “Boom Wear Pad Replacement.”

2. Rapid cycle times with heavy loads.

3. Contaminated, corroded or rusted wear pad sliding surfaces.

4. Operating in extremely dusty/ abrasive conditions.

8. Auxiliary hydraulics will not operate.

9. Excessive chain wear. 1. Improper chain adjustment. 1. Adjust to correct tension. Refer

1. Auxiliary hydraulic system not operating properly.

2. Electronic control function not operating properly.

2. Chain sheave(s) not properly lubricated.

2. Reduce cycle times.

3. Remove contamination and/or corrosion from wear pad sliding surfaces and lubricate. If the surfaces cannot be reconditioned, replace the boom section(s).

4. Clean equipment frequently.

1. Refer to Section 8.4, “Hydraulic Circuits.”

2. Check for DTC. Refer to Section

9.15.8, “Diagnostic Trouble Code (DTC) Table.”

to Section 3.4.1, “Boom Chain Inspection.”- Replace chains as needed.

2. Lubricate chain sheave. Refer to Section 2.5, “Service and Maintenance Schedules.”

G10-55A & G12-55A AccuPlace

3. Chain sheave(s) not rotating freely.

4. Improper chain lubrication. 4. Lubricate at regular intervals.

3. Lubricate chain sheave. Refer to Section 2.5, “Service and Maintenance Schedules.” Repair or replace chain sheave(s) as needed.

Refer to Section 2.5, “Service and Maintenance Schedules.” Replace chains as needed.

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Boom

This Page Intentionally Left Blank

3.22

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Section 4

Cab and Covers

Contents

PARAGRAPH TITLE PAGE

4.1 Operator’s Cab and Covers Component Terminology . . . . . . . . . . . . . . . . . . . . 4.2

4.2 Operator’s Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.2.1 Cab Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.2.2 Serial Number Decal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.3 Cab Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.3.1 Steering Column and Orbitrol Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3

4.3.2 Service Brake Pedal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4

4.3.3 Throttle Pedal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5

4.3.4 Boom Joystick Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5

4.3.5 Frame Level, Auxiliary Hydraulic and Outrigger Joysticks . . . . . . . . . . . . 4.6

4.3.6 Windshield Wiper Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6

4.3.7 Heater/Defroster System (If equipped) . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6

4.4 Cab Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7

4.5 Cab Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9

G10-55A & G12-55A AccuPlace

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Cab and Covers

4.1 OPERATOR’S CAB AND COVERS COMPONENT TERMINOLOGY

To understand the safety, operation and maintenance information presented in this section, it is necessary that the operator/mechanic be familiar with the names and locations of the major assemblies of the machine cab and covers. The following illustration identifies the components that are referred to throughout this section.

FRAME LEVEL INDICATOR

STEERING WHEEL

INSTRUMENT PANEL

TRANSMISSION CONTROL

HEATER AND AC

CONTROLS (optional)

IGNITION SWITCH

LEVER

SERVICE BRAKE PEDAL

BOOM JOYSTICK

FRAME LEVEL JOYSTICK

AUXILIARY HYDRAULIC JOYSTICK

OUTRIGGER JOYSTICKS

MY2780

ACCELERATOR PEDAL

4.2

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Cab and Covers

4.2 OPERATOR’S CAB

WARNING

DO NOT service the machine without following all

safety precautions as outlined in the “Safety Practices” section of this manual. Failure to follow the safety practices could result in death or serious injury.

4.2.1 Cab Safety

WARNING

The protection offered by this ROPS/FOPS will be impaired if subjected to any modification or structural damage, at which time replacement is necessary. ROPS/FOPS must be properly installed using fasteners of correct size and grade, and torqued to their specified value.

DO NOT weld, grind, drill, repair or modify the cab in any way. Any modification or damage to cab structural components requires cab replacement. The lives of the operator and others are potentially at stake.

To help ensure optimum safety, protection and performance, replace the cab if it is damaged. Refer to the appropriate parts manual for ordering information.

4.2.2 Serial Number Decal

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable at the battery negative (-) terminal.

Note: It may be necessary to remove the main dash panel to gain access to the appropriate hydraulic hoses. Refer to Section 9.12.1, “3-N-1 Digital Gauge.”

5. Label, disconnect and cap the four hoses from the side of the steering valve (1). Cap the fittings on the steering valve. Label, disconnect and plug the load sense hose at the front of the steering valve. Cap the fitting on the steering valve.

The cab serial number decal is located on the left side of the cab, behind the seat. Information specified on the serial number plate includes the cab model number, the cab serial number and other data. Write this information down in a convenient location to use in cab correspondence.

4.3 CAB COMPONENTS

4.3.1 Steering Column and Orbitrol Valve

a. Orbitrol Valve Removal

1. Park the machine on a firm, level surface, level the machine, fully retract the boom, lower the boom, place the travel select lever in the (N) NEUTRAL position, engage the parking brake and turn the engine OFF.

2. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

G10-55A & G12-55A AccuPlace

MY0120

6. Remove the steering wheel (2), disconnect and remove the travel select lever (3), disconnect the instrument panel harness connector (4).

7. Remove the steering assembly through the dash panel opening.

8. Support the steering valve, and remove the four hexhead capscrews and four lockwashers.

Note: DO NOT disassemble the orbitrol valve. The orbitrol valve is not serviceable and must be replaced in its entirety, if defective.

4.3

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Cab and Covers

b. Orbitrol Valve Installation

1. Secure the steering valve to the steering column with four hex-flange capscrews and four lockwashers. Apply Loctite

242 threadlock to the

capscrews threads before tightening.

2. Install the steering column through the dash panel opening. Position steering valve to its original orientation in the cab.

3. Install the travel select lever. Torque the capscrews to 30-35 lb-in (3,4-4 Nm). Connect the instrument panel harness connector and install the steering wheel assembly. Torque the steering wheel nut to 29-34 lb-ft (39-46 Nm).

4. Install new o-rings into the steering valve fittings. Lubricate the o-rings with clean hydraulic oil.

5. Uncap and connect the previously labeled load sense hose to the steering valve.

6. Uncap and connect the remaining previously labeled four hoses to the steering valve.

Note: If necessary, install the main dash panel. Refer to Section 9.12.1, “3-N-1 Digital Gauge.”

b. Service Brake Pedal Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

7. Connect the battery negative (-) cable at the battery negative (-) terminal.

8. Carefully examine all connections one last time before engine start-up. Rectify any faulty conditions.

9. Start the engine and check the operation of steering system. Check for hydraulic fluid leaks. Check the hydraulic fluid level in the tank and add fluid as required.

10. Close and secure the engine cover.

c. Steering Test

Conduct a pressure check of the steering hydraulic circuits at the hydraulic manifold valve. Refer to Section

8.3.1, “Pressure Checks and Adjustments.”

4.3.2 Service Brake Pedal

a. Brake Valve Removal/Installation

Refer to Section 8.8.7, “Service Brake Valve,” for removal information.

MAP0270

Note: If necessary, remove the dash from the cab by removing the three bolts, nuts and washers.

5. Remove the bolt and lockwasher (1) securing the service brake pedal pivot pin (2).

6. Pull the pivot pin from the service brake pedal bracket (3).

7. Remove the service brake pedal from the cab.

c. Service Brake Pedal Installation

4.4

1. Position the service brake pedal in its mounting location within the cab.

2. Apply Loctite

Moly Paste #51049 to the pivot pin.

Secure the brake pedal into position with the pivot pin.

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3. Be sure the brake pedal has the correct range of motion. Secure pivot pin with bolt and lockwasher. Apply Loctite 242 threadlock to the bolt threads before tightening.

Note: If necessary, install the dash to the cab by installing the three bolts, nuts and washers.

4. Connect the battery negative (-) cable to the battery negative (-) terminal.

5. Close and secure the engine cover.

4.3.3 Throttle Pedal

a. Throttle Pedal Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

4. Disconnect the electrical harness connector (4).

5. Remove the bolts (5) securing the throttle pedal to the throttle pedal bracket (6).

6. Remove the throttle pedal assembly from the cab.

b. Throttle Pedal Installation

1. Position the throttle pedal in its mounting location

within the cab.

2. Secure the throttle pedal into position with the pivot pin.

3. Install the throttle pedal ball joint to the throttle pedal.

4. Connect the battery negative (-) cable to the battery negative (-) terminal.

5. Close and secure the engine cover.

4.3.4 Boom Joystick Assembly

a. Boom Joystick Assembly Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

4. Remove the plastic right hand panel (7) to gain access to the underside of the boom joystick.

5. Disconnect the electrical harness connector from the joystick.

6. Remove the bolts (8) on the underside of the joystick securing the boom joystick to the cab.

7. Lift the boom joystick from its mounting position.

8. Remove the boom joystick assembly.

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MY0940

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b. Boom Joystick Assembly Installation

1. Connect the electrical harness connector to the joystick.

2. Ensure the rubber sleeve at the base of the joystick is secured over all four corners of the base of the joystick. If necessary, carefully pull the rubber sleeve over the four corners.

3. Place the joystick into the mount and install the bolts securing the boom joystick to the cab. Ensure the rubber sleeve on the joystick stays in place when tightening the bolts.

4. Place the plastic right hand panel into position and secure with bolts. Ensure the rubber sleeve on the joystick remains under the panel.

5. Connect the battery negative (-) cable to the battery negative (-) terminal.

6. Test the joystick functions.

7. Close and secure the engine cover.

4.3.5 Frame Level, Auxiliary Hydraulic and Outrigger Joysticks

5. Label and disconnect the electrical connector to the joystick (10).

6. Remove any hardware securing the joystick to the dash panel.

7. Remove the joystick.

b. Joystick Installation

1. Install the joystick to the RH panel.

2. Connect the previously labeled electrical connector to the joystick.

3. Install the RH panel to its original position with the previously used hardware.

4. Connect the battery negative (-) cable to the battery negative (-) terminal.

5. Test the complete range of the joystick functions:

6. Close and secure the engine cover.

4.3.6 Windshield Wiper Assembly

Refer to Section 9.9, “Window Wiper/Washer Windshield Wiper Motor,” for removal and installation information.

MY2770

a. Joystick Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

4. Remove the screws securing the RH panel (9) to the cab. Remove the RH panel.

4.3.7 Heater/Defroster System (If equipped)

a. Heater Assembly Removal

1. Park the machine on a firm, level surface, level the machine, fully retract the boom, lower the boom, place the travel select lever in the (N) NEUTRAL position, engage the park brake and shut the engine OFF.

2. Place a Do Not Operate Tag on both the ignition key switch and the steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

5. Place a suitable container beneath the radiator. Slowly turn the radiator cap to the first stop, and allow any pressure to escape. Remove the radiator cap.

6. Place a funnel at the base of the radiator to channel the drained coolant into the container. Loosen the drain petcock and allow the coolant to drain.

7. Transfer the coolant to a container with a cover, and label as “Used Antifreeze.” Dispose of the used coolant at an approved recycling facility.

8. Tighten the radiator drain petcock.

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9. Remove the bolts that secure the seat to the cab. Remove the seat.

MY0190

10. Remove the bolts securing the front plate (11) to the seat riser weldment (12).

11. Remove the bolts securing the seat riser weldment to the cab. Remove the riser weldment.

12. Loosen the hose clamps, label and disconnect the heater hoses (13). Cap or plug the hoses to prevent debris from entering the heater system.

4. Install the seat riser weldment.

5. Install the front plate to the seat riser weldment.

6. Install the cab seat.

7. Fill the cooling system completely with a 50/50 mixture of ethylene glycol and water, allowing time for the coolant to fill the engine block. The cooling system capacity is listed in Section 2.4, “Fluid and Lubricant Capacities.”

8. Connect the battery negative (-) cable to the battery negative (-) terminal.

Note: When the engine is initially started, run it briefly at low idle and check the machine for any visual sign of fluid leakage. STOP the engine immediately if any leakage is noted, and make any necessary repairs before continuing.

9. Wait for the engine to cool and check the coolant level. Add coolant as required to bring the coolant to the proper level.

4.4 CAB REMOVAL

WARNING

MY2790

13. Label and disconnect any electrical connections.

14. Remove the bolts securing the heater assembly to the cab. Remove the heater assembly.

b. Heater Assembly Installation

1. Position the heater assembly to its original orientation in the cab. Secure with the previous hardware.

2. Connect the previously labeled electrical connections.

3. Connect the previously labeled heater hoses to their appropriate locations.

G10-55A & G12-55A AccuPlace

Note: To help ensure safety and optimum performance, replace the cab if it is damaged. Refer to the appropriate parts manual for ordering information.

Inspect the cab, its welds and mounts. If modification, damage, a cracked weld and/or fatigued metal is discovered, replace the cab. Contact the JLG distributor or the JLG Service Department with any questions about the suitability or condition of a cab.

Note: Remove and label cab components as needed before removing the cab from the machine. Label, disconnect and cap hydraulic hoses. Transfer cab parts to the replacement cab after the replacement cab is securely mounted on the machine.

1. Park the machine on a firm, level surface. Allow sufficient overhead and side clearance for cab removal. Level the machine, fully retract the boom, lower the boom, place the travel select lever in the (N) NEUTRAL position, engage the park brake and shut the engine OFF.

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2. Block all four wheels to help prevent the machine from moving. Ensure that there is sufficient overhead and side clearance for cab removal.

3. Open the engine cover. Allow the system fluids to cool.

4. Disconnect the battery negative (-) cable at the battery negative (-) terminal.

5. Place a funnel at the base of the radiator to channel the drained coolant into the container. Loosen the drain petcock and allow the coolant to drain.

6. Transfer the coolant to a container with a cover, and label as “Used Antifreeze.” Dispose of the used coolant at an approved recycling facility.

7. Tighten the radiator drain petcock.

8. Disconnect the cab heater hoses. Refer to Section

4.3.7, “Heater/Defroster System (If equipped).”

9. Remove the necessary dash panels to gain access to the electrical wiring connections. Label and disconnect the harnesses. Push the harness connectors through the opening in the cab.

10. Remove the boom joystick from the mounting position. Refer to Section 4.3.4, “Boom Joystick Assembly.” Label and disconnect the electrical harness attached to the boom joystick.

11. Remove the frame level and attachment tilt and auxiliary hydraulic joysticks. Refer to Section 4.3.5, “Frame Level, Auxiliary Hydraulic and Outrigger Joysticks.” Label and disconnect the electrical harnesses attached to the joysticks.

12. Label, disconnect and cap all hydraulic hoses attached to the steering orbitrol valve. Cap all fittings and openings to keep dirt and debris from entering the hydraulic system.

13. Label, disconnect and cap all hydraulic hoses attached to the steering orbitrol valve. Cap all fittings and openings to keep dirt and debris from entering the hydraulic system.

14. Label, disconnect and cap all hydraulic hoses attached to the service brake valve. Cap all fittings and openings to keep dirt and debris from entering the hydraulic system.

15. Push all the hydraulic hoses through the opening in the cab.

16. Disconnect the throttle cable from the throttle assembly. Refer to Section 4.3.3, “Throttle Pedal.”

17. Disconnect the engine air filter and hydraulic oil reservoir breather from their brackets at the top of the cab. Move the air filter and breather clear from

the cab so they do not become damaged during cab removal.

18. Remove the fuel tank from the cab. Refer to Section

7.4.2, “Fuel Tank.”

19. Route a sling with a suitable lifting capacity under the inner six braces (14) and behind the center cross support above the wind shield.

MY0610

20. Remove the two cab side-mount bolts, washers, isolators and nuts (15) in the cab.

21. Remove the four lower cab-to-frame bolts, washers and nuts (16).

MAP0160

22. Remove the mirrors and all other cab components as needed, if not previously removed.

23. Carefully begin to lift the cab. Stop and check that all wiring, hydraulic hoses and fasteners are disconnected or removed.

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24. When all wiring, hydraulic hoses and fasteners are disconnected or removed, carefully and slowly lift the cab and remove it from the frame. Readjust the position of the sling as needed to help balance the cab during removal.

25. When the cab is completely clear of the machine, carefully lower it to the ground. Block up or support the cab so that it does not move or fall. Ensure that no personnel enter the cab while it is being removed from the machine.

26. Inspect the condition of the fittings, clamps, hydraulic hoses, etc. Replace parts as indicated by their condition.

27. Inspect and replace other machine parts that are exposed with the cab removed. Repair or replace as required.

4.5 CAB INSTALLATION

1. Block all four wheels to help prevent the machine from moving. Ensure that there is sufficient overhead and side clearance for cab installation.

2. Route a sling with a suitable lifting capacity around the inner six braces (13) and behind the center cross support above the wind shield.

3. Use a hoist or overhead crane and sling attached to the cab. Carefully begin to align the cab with the mounting holes in the frame. Stop and check that wiring, hydraulic hoses, cables, etc., will not be pinched or damaged as the cab is positioned. Readjust the position of the sling as needed to help balance the cab during installation.

4. Install the four lower cab-to-frame mount bolts, washers and nuts to 280-305 lb-ft (380-414 Nm).

5. Install the two cab side mount bolts, washers, isolators and nuts to 680-720 lb-ft (922-976 Nm).

6. Install the engine air filter and hydraulic oil reservoir breather to their brackets at the top of the cab.

7. Install the throttle cable to the throttle pedal assembly. Refer to Section 4.3.3, “Throttle Pedal.”

8. Pull all the hydraulic hoses and electrical wires through the cab.

9. Uncap and reconnect the previously labeled hydraulic hoses to their appropriate locations.

10. Reconnect the previously labeled electrical connections to their appropriate locations.

11. For machines equipped with the heater option, reconnect the heater hoses to the cab heater. Refer to Section 4.3.7, “Heater/Defroster System (If equipped).”

12. Install the fuel tank to the cab. Refer to Section 7.4.2, “Fuel Tank.”

13. Fill the cooling system completely with a 50/50 mixture of ethylene glycol and water, allowing time for the coolant to fill the engine block. The cooling system capacity is listed in Section 2.4, “Fluid and Lubricant Capacities.”

14. Connect the battery negative (-) cable to the battery negative (-) terminal.

15. Carefully examine all cab components, fasteners, etc., one last time before engine start-up. Rectify any faulty conditions.

16. Start the engine and check the operation of all controls. Check for hydraulic fluid leaks. Check the hydraulic fluid level in the tank and add fluid as required.

17. Wait for the engine to cool and check the coolant level. Add coolant to the overflow bottle as required to bring the coolant to the proper level.

18. Install the mirrors and all other cab components as needed, if removed.

19. Unblock the wheels.

20. Close and secure the engine cover.

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4.10

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Section 5

Axles, Drive Shafts, Wheels and Tires

Contents

PARAGRAPH TITLE PAGE

5.1 Axle, Drive Shaft and Wheel Component Terminology. . . . . . . . . . . . . . . . . . . . 5.2

5.2 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3 Axle Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3.1 Axle Serial Number Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3.2 Axle Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3.3 Axle Internal Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3.4 Axle Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3

5.3.5 Axle Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4

5.3.6 Axle Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4

5.3.7 Axle Assembly and Drive Shaft Troubleshooting . . . . . . . . . . . . . . . . . . . 5.6

5.4 Drive Shafts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.4.1 Drive Shaft Inspection and Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.4.2 Drive Shaft Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.4.3 Drive Shaft Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.4.4 Drive Shaft Cleaning and Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.4.5 Drive Shaft Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9

5.5 Wheels and Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.10

5.5.1 Removing Wheel and Tire Assembly from Machine. . . . . . . . . . . . . . . . . 5.10

5.5.2 Installing Wheel and Tire Assembly onto Machine . . . . . . . . . . . . . . . . . . 5.11

5.6 Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11

5.7 Towing a Disabled machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11

5.7.1 Manually Releasing the Park Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.11

5.7.2 Manually Resetting the Park Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.12

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5.1 AXLE, DRIVE SHAFT AND WHEEL COMPONENT TERMINOLOGY

To understand the safety, operation and maintenance information presented in this section, it is necessary that the operator/mechanic be familiar with the names and locations of the major assemblies of the axles, drive shafts, wheels and tires. The following illustration identifies the components that are referred to throughout this section.

REAR STEERING

ASSEMBLY

FRONT AXLE

ASSEMBLY

FRONT STEERING

CYLINDER

TRANSMISSION

DROPBOX

FRONT AXLE WHEEL HUBS (2)

REAR DRIVE SHAFT

FRONT DRIVE SHAFT

REAR AXLE

ASSEMBLY

REAR AXLE HUBS (2)

MAP0170

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5.2 GENERAL INFORMATION

WARNING

DO NOT service the machine without following all

safety precautions as outlined in Section 1, “Safety Practices,” of this manual. Failure to follow the safety practices could result in death or serious injury.

Note: To help ensure optimum performance, the drive shaft assemblies are specially balanced as a unit at the factory. When servicing any flange yoke, slip yoke or drive shaft tube, order a complete assembly if components are bent or damaged. Refer to the appropriate parts manual for ordering information.

Before performing any inspection, maintenance or service operation, thoroughly clean the unit. The axles and drive shafts should be checked and repaired only by experienced service technicians who are aware of all safety instructions and particular component features.

Use suitable products to thoroughly clean all disassembled mechanical parts to help prevent personal injury to the worker and prevent damage to the parts. Carefully inspect the integrity of all moving parts (bearings, yokes, tubes, gears, shafts, etc.) and fasteners (nuts, bolts, washers, etc.) as they are subject to major stress and wear. Always replace elastic locknuts and any damaged, worn, cracked, seized or otherwise improper parts that could affect the safe and proper functioning of the machine, axles and drive shafts.

5.3 AXLE ASSEMBLIES

5.3.1 Axle Serial Number Plate

The front and rear axle serial number plate is located on a mounting pad on the front side of the center section of each axle. Information on the serial number plate is required in correspondence regarding the axle.

Supply information from the axle serial number plate when communicating about an axle assembly or axle components.

5.3.2 Axle Specifications

General axle specifications are found in Section 2.4, “Fluid and Lubricant Capacities.”

5.3.3 Axle Internal Service

Detailed axle service instructions (covering the axle, differential, brakes and wheel-end safety, repair, disassembly, reassembly, adjustment and troubleshooting information) are provided in the MO213S10 213 Dana Axle Repair Manual (JLG P/N 31200240).

5.3.4 Axle Maintenance

CLEANING: Clean parts with machined or ground

surfaces (such as gears, bearings and shafts) with emulsion cleaners or petroleum-based cleaners. DO NOT steam clean internal components and the interior of the planetary hub and axle housing. Water can cause corrosion of critical parts. Rust contamination in the lubricant can cause gear and bearing failure. Remove old gasket material from all surfaces.

DRYING: Use clean, lintless towels to dry components after cleaning. DO NOT dry bearings by spinning them with compressed air; this can damage mating surfaces due to lack of lubrication. After drying, lightly coat components with oil or a rust-preventive chemical to help protect them from corrosion. If storing components for a prolonged period, wrap them in wax paper.

PERIODIC OPERATION REQUIREMENT: Every two weeks, drive the machine far enough to cause the drivetrain components to make several complete revolutions. This will help ensure that internal components receive lubrication to minimize deterioration caused by environmental factors such as high humidity.

SUBMERSION: If the machine has been exposed to water deep enough to cover the hubs, disassemble the wheel ends and inspect for water damage and contamination. If the carrier housing was submerged in water, especially if the water level was above the vent tube (breather), drain the axle and inspect internal parts for water damage and contamination. Before assembling and refilling the unit with the specified lubricant(s), clean, examine and replace damaged parts as necessary.

Note: Use a suitable puller for bearing removal. Clean, inspect and lubricate all bearings just prior to reassembly. If replacement of a damaged bearing cup or cone is necessary, replace the cup and cone as a set.

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5.3.5 Axle Removal

The front and rear axle assemblies differ in that the front axle assembly is equipped with a parking brake mechanism and a limited-slip feature; the rear axle has neither. The following steps outline a typical axle removal procedure, suitable for either the front or the rear axle assembly.

Cleanliness is extremely important. Before attempting to remove the axle, thoroughly clean the machine. Avoid spraying water or cleaning solution on the stabilizer solenoids and other electrical components. If using a steam cleaner, seal all openings before steam cleaning.

Note: Clear the work area of all debris, unnecessary personnel, etc. Allow sufficient space to raise the machine and to remove the axle.

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

5. Remove the optional fender assembly.

6. If the axle will be disassembled after removal, place a suitable receptacle under the axle (1) and wheel hubs drain plugs. Remove the drain plugs and allow the axle oil to drain into the receptacle. Transfer the used axle oil into a suitable covered container, and label the container as “Used Oil.” Dispose of used oil at an approved recycling facility.

MY0840

(in rear)

7. Label, disconnect and cap the steering and brake lines at the axle. Wipe up any spilled oil.

8. Block the front and rear of both tires on the axle that is not being removed. Ensure that the machine will remain in place during axle removal before proceeding.

9. Raise the machine using a suitable jack or hoist. Place suitable supports under both sides of the frame and lower the machine onto the supports. Ensure that the machine will remain in place during axle removal.

10. Support the axle that is being removed with a suitable jack, hoist or overhead crane and sling. DO NOT raise the axle or the machine.

11. Remove both wheel and tire assemblies from the axle that is being removed. Refer to Section 5.5.1, “Removing Wheel and Tire Assembly from Machine.”

Note: The wheel and tire assemblies must be re-installed later with the directional tread pattern “arrows” facing in the direction of forward travel.

12. Remove the drive shaft assembly. Refer to Section

5.4.3, “Drive Shaft Removal.”

13. Remove the bolts and locknuts securing the axle to the frame.

14. Remove the axles from the machine using the jack, hoist or overhead crane and sling supporting the axle. DO NOT raise or otherwise disturb the machine while removing the axle. Balance the axle and prevent it from tipping, turning or falling while removing it from beneath the machine. Place the axle on a suitable support or holding stand.

5.3.6 Axle Installation

1. Before proceeding, ensure that the machine will remain in place during axle installation. Block the front and rear of both tires on the axle that is already installed on the machine.

2. If applicable, raise the machine using a suitable jack or hoist. Place suitable supports beneath the frame and lower the machine onto the supports, allowing enough room for axle installation. Ensure that the machine will remain in place during axle installation.

3. Using a suitable jack, hoist or overhead crane and sling, remove the axle from its support or holding stand. Balance the axle and prevent it from tipping, turning or falling while positioning it beneath the machine. DO NOT raise or otherwise disturb the machine while installing the axle. Keep the axle supported and balanced on the jack, hoist or overhead crane and sling throughout the installation procedure.

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4. Position the axle under the frame, and align the axle housings with the holes in the frame.

5. Install the four axle bolts and nuts. Apply Loctite

242 threadlock to the bolt threads and torque to 530-565 lbft (718-766 Nm).

6. Move the cylinder into position on the axle cylinder anchor. Insert a cylinder-mount pin through the cylinder and cylinder anchor. Secure the cylindermount pin with one capscrew and a new locknut.

7. Apply multi-purpose grease through the self-tapping lube fitting to lubricate the self-align bearing and the cylinder-mount pin.

8. Install the drive shaft assemblies. Refer to Section

5.4.5, “Drive Shaft Installation.”

9. If reinstalling an axle previously removed from the machine, position the driveshaft yoke on the axle according to the alignment marks made earlier. If installing a new axle, note the position of the driveshaft yoke at the transmission. Align the driveshaft yoke on the axle in the same plane as the yoke on the transmission.

10. Tighten the axle oil drain plug, loosen and remove the axle oil fill plug (2). Refer to Section 2.4, “Fluid and Lubricant Capacities,” for proper oil and capacities.

11. Rotate wheel hubs 90 degrees so the drain plug becomes the fill plug (3). Refer to Section 2.4, “Fluid and Lubricant Capacities,” for proper oil and capacities.

Note: ALWAYS use new o-rings when servicing the machine.

16. Install new o-rings into the fittings. Lubricate the o-rings with clean hydraulic oil.

17. Uncap and connect the steering and brake lines at their axle fittings.

18. Check the hydraulic reservoir oil level.

19. Start the engine. Turn the steering wheel several times lock to lock, operate the frame tilt function several times in both directions and check the function of the brakes. Check for hydraulic leaks, and tighten or repair as necessary.

20. Install the optional fender assembly.

21. Close and secure the engine cover.

Note: The service brake circuit will need to be bled after axle installation. Refer to Section 8.8.8, “Brake Test.”

MT0220

12. Install the wheel and tire assemblies. Refer to Section 5.5.2, “Installing Wheel and Tire Assembly onto Machine.”

13. Carefully remove the jack, hoist or overhead crane and sling supporting the axle.

14. Carefully raise the machine using a suitable jack or hoist. Remove the supports from beneath the frame and lower the machine to the ground.

15. Remove the blocks from the front and rear of both tires on the other axle.

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5.3.7 Axle Assembly and Drive Shaft Troubleshooting

Problem Cause Remedy

1. Excessive axle noise while driving.

1. Oil level too low. 1. Fill oil to correct level. Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Axle and/or wheel end housings

filled with incorrect oil or oil level low.

2. Drain axle and/or wheel end housings and fill to correct level with Mobilfluid 424

(ISO 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

3. Incorrect alignment of ring and pinion gears.

4. Incorrect pinion (input) shaft bearing preload.

3. Correct alignment by adding or removing shims as needed.

4. Correct bearing preload by adding or removing shims as needed.

5. Worn or damaged bearings. 5. Replace bearings as needed.

6. Worn or broken gear teeth. 6. Replace gears as needed.

7. Contamination in the axle. 7. Drain axle and/or wheel end housings and fill to correct level with Mobilfluid 424

(ISO 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Intermittent noise when traveling.

3. Vibration or intermittent noise when traveling.

8. Axle housing damaged. 8. Replace damaged parts.

1. Universal joint(s) worn or damaged.

2. Differential ring and/or pinion gears damaged.

1. Drive shaft universal joint assembly(ies) incorrectly

1. Repair or replace universal joints as needed.

2. Determine cause and repair as needed.

1. Tighten capscrews to correct torque.

tightened.

2. Drive shaft universal joint(s) worn or damaged.

3. Drive shaft(s) damaged/ unbalanced.

2. Repair or replace universal joints as needed.

3. Replace drive shaft(s) as needed.

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Axles, Drive Shafts, Wheels and Tires

Problem Cause Remedy

4. Oil leaking from axle (differential housing and/or axle housings).

1. Drain and/or inspection plugs loose and/or o-rings damaged or missing.

2. Hose fittings loose. 2. Tighten fittings.

3. Axle shaft seal damaged or missing and/or worn or damaged shaft sealing surfaces.

4. Input shaft multi-seal ring damaged or missing and/or worn or damaged pinion (input) shaft sealing surfaces.

5. Axle casing to brake housing and/or brake housing to differential assembly o-rings and/or seals worn or damaged.

6. Axle housing mounting nuts and capscrews loose.

7. Differential and/or axle housing(s) damaged.

1. Replace o-rings as needed and tighten plugs to 96 lb-ft (130 Nm).

3. Replace seal and/or joint coupling fork shaft (axle shaft).

4. Replace o-rings as needed and tighten plugs to 96 lb-ft (130 Nm).

5. Replace o-rings and seals.

6. Tighten housing nuts and capscrews to 288 lb-ft (390 Nm).

7. Replace housing(s) as needed.

5. Oil leaking from wheel end housing (planet carrier).

6. Oil leaking from steering cylinder.

1. Oil level plugs loose and/or o-rings damaged or missing.

2. O-ring between hub and housing (planet carrier) damaged or missing.

3. Shaft seal damaged or missing and/or worn or damaged shaft sealing surfaces.

4. Housing capscrews loose. 4. Tighten housing capscrews to

5. Housing (planet carrier) damaged. 5. Replace housing (planet carrier).

1. Hose fittings loose. 1. Tighten fittings.

2. Steering cylinder o-rings and/or seals worn or damaged.

3. Piston rod seal worn or damaged.

4. Cylinder tube damaged. 4. Replace cylinder tube.

1. Replace o-rings as needed and tighten plugs to 96 lb-ft (130 Nm).

2. Replace o-ring.

3. Replace seal and/or fork joint shaft.

41 lb-ft (55 Nm).

2. Replace o-rings and seals.

3. Replace piston rod seal.

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Axles, Drive Shafts, Wheels and Tires

Problem Cause Remedy

7. Axle overheating. 1. Oil level too high. 1. Fill oil to correct level with

Mobilfluid 424

(ISO 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Axle and/or wheel end housings filled with incorrect oil or oil contaminated or oil level low.

2. Drain axle and fill to correct level

with Mobilfluid 424

(ISO 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

3. Dragging park brake. 3. Adjust park brake cable as needed.

8. High steering effort required. 1. Steering (hydraulic) system not operating properly.

2. Excessive joint housing swivel bearing preload.

1. Refer to Section 8.4, “Hydraulic Circuits.”

2. Correct bearing preload by adding or removing shims as needed.

3. Worn or damaged swivel bearings.

9. Slow steering response. 1. Steering (hydraulic) system not operating properly.

2. Steering cylinder leaking internally.

3. Replace swivel bearings as needed.

1. Refer to Section 8.4, “Hydraulic Circuits.”

2. Repair or replace steering cylinder as needed.

10. Excessive noise when brakes

1. Brake discs worn. 1. Check brake discs for wear.

are engaged.

2. Brake discs damaged. 2. Replace brake discs.

11. Brakes will not engage. 1. Brake (hydraulic) system not operating properly.

2. Brake piston o-rings and seals damaged (leaking).

12. Brakes will not hold the

1. Brake discs worn. 1. Check brake discs for wear.

machine or braking power reduced.

2. Brake (hydraulic) system not operating properly.

3. Brake piston o-rings and seals damaged (leaking).

Refer to Section 2.4, “Fluid and Lubricant Capacities.”

1. Refer to Section 8.8.8, “Brake Te st.”

2. Replace o-rings and seals.

Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Refer to Section 8.8.8, “Brake Te st.”

3. Replace o-rings and seals.

5.8

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Axles, Drive Shafts, Wheels and Tires

5.4 DRIVE SHAFTS

5.4.1 Drive Shaft Inspection and Service

Whenever servicing the machine, conduct a visual inspection of the drive shafts and cross and bearing assemblies (universal joints, or U-joints). A few moments spent doing this can help prevent further problems and down time later.

Inspect areas where the drive shaft flange yokes and slip yokes mount to the drive shafts. Attempt to turn each drive shaft in both directions. Look for excessive looseness, missing parts, cracks or other damage. Worn or damaged drive shafts and cross and bearing assemblies may cause an excessive amount of vibration or noise.

5.4.2 Drive Shaft Maintenance

Refer to Section 2.4, “Fluid and Lubricant Capacities,” for information regarding the lubrication of the grease fittings on the drive shafts.

5.4.3 Drive Shaft Removal

7. Remove the four capscrews and two straps securing the bearing cross to the transmission output shaft flange.

8. Remove the four capscrews and two straps securing the bearing crosses to the axle.

9. Remove the front drive shaft assembly.

10. Repeat the above procedure on the second front drive shaft and rear drive shaft.

To Tr ansmi ss io n

MT0350To Axle

Note: The drive shaft assemblies are balanced assemblies. Mark the yoke and axle, transmission, transfer case, and the shaft and slip yoke so that these components can be returned to their original positions when reinstalled. Yokes at both ends of the drive shaft must be in the same plane to help prevent excessive vibration.

1. Park the machine on a firm, level surface, level the machine, fully retract the boom, lower the boom, place the transmission control lever in (N) NEUTRAL, engage the park brake and shut the engine OFF.

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Disconnect the battery negative (-) cable from the battery negative (-) terminal.

5. Block the wheels.

6. The drive shaft assembly is a balanced assembly. Mark the yoke and axle, transmission and the shaft and slip yoke so that these components can be returned to their original positions when reinstalled. Yokes at both ends of the drive shaft must be in the same plane to help prevent excessive vibration.

5.4.4 Drive Shaft Cleaning and Drying

1. Disassemble and clean all parts using an approved cleaning fluid. Allow to dry.

2. Remove any burrs or rough spots from all machined surfaces. Re-clean and dry as required.

5.4.5 Drive Shaft Installation

1. Raise the drive shaft assembly into position. The slip-yoke end of the drive shaft mounts toward the axle. If reinstalling a drive shaft previously removed, align the flange yokes according to the alignment marks made during removal.

2. Install the four capscrews and two straps securing the bearing crosses to the transmission.

Note: Do not re-torque strap capscrews. Replace old capscrews with new capscrews and torque to 55-60 lb-ft (75-81 Nm). Apply Loctite threads before tightening.

3. Install the four capscrews and two straps securing the bearing crosses to the axle.

4. Repeat the above procedure on the remaining front drive shaft and rear drive shaft.

5. Connect the battery negative (-) cable to the battery negative (-) terminal.

6. Close and secure the engine cover.

7. Unblock the wheels.

242 threadlock to capscrew

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Axles, Drive Shafts, Wheels and Tires

5.5 WHEELS AND TIRES

WARNING

Risk of death or serious personal injury. Mismatched tire sizes, ply ratings or mixing of tire types (radial tires with bias-ply tires) may compromise machine stability and could cause machine to tip over.

JLG recommends a replacement tire to be the same size, ply and brand as originally installed. Refer to the appropriate parts manual for ordering information. If not using a JLG approved replacement tire, JLG recommends that replacement tires have the following characteristics:

• Equal or greater ply/load rating and size of original.

• Tire tread contact width equal or greater than

original.

• Wheel diameter, width and offset dimensions equal to the original.

• Approved for the application by the tire manufacturer (including inflation pressure and maximum tire load).

The rims installed have been designed for stability requirements which consist of track width, tire pressure and load capacity. Size changes such as rim width, center piece location, larger or smaller diameter, etc., without written factory recommendations, may result in unsafe condition regarding stability.

Foam filled tires have a positive effect on the weight, stability and handling characteristics of the machine, especially under load. JLG does not recommend the use of hydrofill as a tire-fill substance because of possible environmental impact.

Large-bore valve stems are used to help expedite tire inflation and deflation. An inner tube may be used if a tire does not provide an airtight seal. Check tire inflation pressures when the tires are cold. When mounting a tire on the wheel, the tire must be mounted on the wheel respective of the directional tread pattern of the tire; this produces a left or right tire and wheel assembly.

The wheel and tire assemblies must be installed with the directional tread pattern “arrows” (4) facing in the direction of forward travel.

MAH0890

5.5.1 Removing Wheel and Tire Assembly from Machine

1. Park the machine on a firm, level surface, fully retract the boom, lower the boom, place the transmission control lever in (N) NEUTRAL, engage the park brake and shut the engine OFF.

2. Place an Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Loosen but DO NOT remove the lug nuts on the wheel and tire assembly to be removed.

4. Place a suitable jack under the axle pad closest to the wheel being removed. Raise the machine and position a suitable support beneath the axle. Allow sufficient room to lower the machine onto the support and to remove the wheel and tire assembly.

5. Lower the machine onto the support.

6. Remove lug nuts and lug washers in an alternating pattern.

7. Remove the wheel and tire assembly from the machine.

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Axles, Drive Shafts, Wheels and Tires

5.5.2 Installing Wheel and Tire Assembly onto Machine

Note: The wheel and tire assemblies must be installed with the directional tread pattern “arrows” facing in the direction of forward travel.

Install tires onto wheels

to rotate in proper direc-

tion

Tread “arrows” must point

forward

5.6 BRAKES

Check the brake disks for wear every 1,000 hours of operation or yearly.

For more information on brake disk inspection, refer to the appropriate axle repair manual.

5.7 TOWING A DISABLED MACHINE

Towing a disabled machine should only be attempted as a last resort, after exhausting all other options. Make every effort to repair the machine, and move it under its own power, before using the emergency towing procedures outlined below.

IMPORTANT: Block the wheels of the machine BEFORE attempting to release the park brake. Once the park brake is released, the machine’s park brake AND service brakes are inoperable.

5.7.1 Manually Releasing the Park Brake

MAH0460

1. Position wheel onto studs on wheel end of axle.

2. Install wheel lug washers.

3. Start all nuts by hand to prevent cross threading. DO NOT use a lubricant on threads or nuts.

4. Tighten lug nuts in an alternating pattern as indicated in figure. Torque to 350-400 lb-ft (475-542 Nm).

OY1220

5. Remove machine from supports.

MZ1020

1. Loosen the nuts of the screws (5) for the manual release of the braking units. Draw the nuts back approximately 6 mm.

2. Tighten the screws until they are gently seated on the driving plate

3. Carefully tighten each release screw a 1/4 turn at a time in sequence until all have been turned on full turn 360°.

4. Repeat steps 1 thru 3 for the other side of the differential.

Note: After the machine has been towed to a secure location, reactivate the parking brake. Carefully follow the procedures from start to finish. Consult your local JLG distributor or the JLG Service Department if you are unsure about any part of the procedure, or for specific instructions concerning your particular situation.

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Axles, Drive Shafts, Wheels and Tires

5.7.2 Manually Resetting the Park Brake

Note: Block the wheels of the machine BEFORE attempting to reset the machine’s park brake. Once the park brake is released, the machine’s park brake AND service brakes are inoperable.

1. Loosen each release screw, only 1/4 turn at a time, in sequence, until each screw has lost contact with the guide pin.

2. Remove the screws along with the nuts and seals. Replace the seals, lubricate the screws with a silicone-based grease and re-install the screws along with the nuts.

3. Adjust the nut of the screw heads in relation to the arm by 30 mm (1.18 in).

4. Repeat steps 1 thru 3 for the other side of the differential.

5. After repairs to the machine have been made, start the machine and check the park brake and service brakes for proper function.

5.12

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Section 6

Transmission

Contents

PARAGRAPH TITLE PAGE

6.1 Transmission Assembly Component Terminology . . . . . . . . . . . . . . . . . . . . . . . 6.2

6.2 Transmission Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.3 Transmission Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.4 Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.4.1 Transmission Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.4.2 Transmission Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.5 Transmission Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

6.5.1 Transmission Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4

6.5.2 Transmission Inspection and Internal Repair . . . . . . . . . . . . . . . . . . . . . . 6.5

6.5.3 Transmission Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5

6.5.4 After Transmission Service or Replacement . . . . . . . . . . . . . . . . . . . . . . . 6.6

6.6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7

6.6.1 Transmission Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7

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Transmission

6.1 TRANSMISSION ASSEMBLY COMPONENT TERMINOLOGY

To understand the safety, operation and maintenance information presented in this section, it is necessary that the operator/mechanic be familiar with the names and locations of the major assemblies of the transmission. The following illustration identifies the components that are referred to throughout this section.

TRANSMISSION

FILTER

TRANSMISSION BREATHER

SHIFT SOLENOIDS

OIL DRAIN PLUG

OIL FILLER PLUG

TRANSFER CASE

BREATHER

PARK BRAKE SOLENOIDS

OIL FILL TUBE AND DIPSTICK

6.2

OIL DRAIN PLUG

MAP0680

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Transmission

6.4.2 Transmission Maintenance Schedule

WARNING

DO NOT service the machine without following all

safety precautions as outlined in Section 1, “Safety Practices,” of this manual. Failure to follow the safety practices could result in death or serious injury.

6.2 TRANSMISSION DESCRIPTION

Instructions in this section pertain mainly to general specifications, towing, maintenance information, and transmission removal and installation procedures. for internal transmission service instructions and detailed specifications contact your local JLG distributor for a copy of the ZF Repair Manual P/N 5872 135 002 (JLG P/N 31200241).

6.3 TRANSMISSION SERIAL NUMBER

The transmission serial number plate is located on the front of the transmission case behind the oil dipstick. Information specified on the serial number plate includes the transmission model number, the transmission serial number and other data. Information on the serial number plate is required in correspondence regarding the transmission.

6.4 TRANSMISSION SPECIFICATIONS

6.4.1 Transmission Maintenance

Cleanliness is of extreme importance. Before attempting any repairs, thoroughly clean the exterior of the transmission to help prevent dirt from entering while performing maintenance checks and procedures.

Section 6.4.2, “Transmission Maintenance Schedule,” provides a suggested maintenance schedule with references to pertinent procedures and instructions in this manual. To help prevent transmission problems before they occur, follow the maintenance schedule.

Note: Lubrication and Maintenance chart decals are located inside the engine compartment access door. These decals contain a general maintenance schedule that should be followed to maintain the machine in good operating condition. Refer to Section 2, “General Information and Specifications.” The same schedule information is presented in the appropriate Operation & Safety Manual, with a detailed account of how to perform the procedures.

Complete transmission maintenance information is located in the appropriate Operation & Safety Manual.

• At ten hour intervals, check the transmission oil level. Refer to the appropriate Operation & Safety Manual.

• When the machine completes its first 50 hours of use, change the transmission filter and oil. Refer to the appropriate Operation & Safety Manual.

• At 1,000 hour intervals, change the transmission oil and filter. Refer to the appropriate Operation & Safety Manual.

Periodically, depending on operating conditions and other factors, back flush the transmission oil cooler, which is located in or behind the radiator. ALWAYS back flush the transmission oil cooler after removing the transmission for repair or replacement.

The transmission oil cooler outlet hose, routed to the lower oil cooler fitting, is located on the top of the transmission. The transmission oil cooler inlet hose, routed to the upper oil cooler fitting, is located on the top of the transmission. (Refer to Section 7.2.3, “Radiator Replacement.”)

Disconnect and back flush the oil cooler portion of the radiator or the oil cooler (located behind the radiator) with oil and compressed air until all foreign material is removed. If necessary, remove the radiator or oil cooler from the machine, and clean the oil cooler circuit using oil, compressed air and steam.

IMPORTANT: DO NOT use flushing compounds for cleaning purposes.

6.5 TRANSMISSION REPLACEMENT

Note: Contact the JLG Service Department if internal transmission repair is required during the warranty period.

Note: To help ensure safety and optimum performance, replace the transmission if it is damaged. Refer to the appropriate parts manual for ordering information.

Cleanliness is of extreme importance. Before attempting to remove the transmission, thoroughly clean the exterior of the transmission to help prevent dirt from entering during the replacement process. Avoid spraying water or cleaning solution onto or near the transmission shift solenoids and other electrical components.

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Transmission

6.5.1 Transmission Removal

WARNING

Risk of severe personal injury. NEVER lift a transmission alone; enlist the help of at least one assistant or use a suitable hoist or overhead crane and sling.

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove engine cover to allow easier access to the transmission.

5. Drain the hydraulic oil reservoir. Refer to Section

8.6.1, “Hydraulic Oil Reservoir Draining.”

6. Disconnect the (+) positive and (-) negative battery cables and remove the battery.

7. Thoroughly clean the transmission and surrounding area, including all hoses and fittings, before proceeding.

8. Place a suitable receptacle under the transmission drain plug (1). Remove the transmission drain plug, and allow the transmission oil to drain into the receptacle. Repeat drain procedure with the drop box (2).

MY0980

9. Transfer the used transmission oil into a suitable, covered container, and label the container as “Used Oil.” Dispose of used oil at an approved recycling facility. Clean and reinstall the transmission drain plug.

10. Remove the transmission-to-axle drive shafts. Refer to Section 5.4.3, “Drive Shaft Removal.”

11. Remove air cleaner unit and intake tubes.

12. Remove the hydraulic pump. Refer to Section 8.7.3, “Pump Replacement.”

13. Label and disconnect the transmission temperature switch connector and shift solenoid wiring harness connectors.

14. Label, disconnect and cap the transmission oil cooler inlet and outlet hoses at the transmission.

15. Remove the access plug from the bottom of the engine bell housing. This will allow access to remove the four bolts holding the torque convertor diaphragm to the engine flywheel.

16. Turn the engine over slowly by hand and align each of the four torque convertor diaphragm bolts to be accessed. Remove them one at a time.

17. Wipe up any spilled hydraulic and transmission oil.

18. Connect a lifting strap or chain to the lifting eye at the top of the transmission, and to a suitable hoist or overhead crane. Operate the hoist or crane to remove slack from the chain, but DO NOT raise the transmission at this time.

19. Place blocks under rear of engine for support BEFORE transmission mounts are removed.

20. Place blocks under the transmission to help support it during removal.

21. Remove both rear transmission mount bolts and lockwashers securing the transmission mount to the frame.

22. Remove the twelve bolts and washers holding the transmission to the engine.

23. Remove the capscrews and lockwashers securing each rear transmission mount to the transmission.

24. Carefully remove the transmission from the machine. Avoid causing damage to the transmission or surrounding parts.

25. Lift the transmission clear of the machine, and lower it onto suitable supports or secure it to a stand built especially for transmission or engine service. Secure the transmission so that it will not move or fall.

6.4

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Transmission

26. Remove any external transmission components as required, including the transmission temperature switch, and inlet and outlet cooler hose fittings. Cover all transmission openings.

MAP0690

27. Remove the transmission oil filter (3) and dispose of properly. Clean the filter mounting surface. Cover or cap the oil filter mount.

28. If transmission oil is suspect to contamination or torque converter is damaged, remove the converter and flex plate from the transmission.

29. Remove the bolt and washers holding the converter to the flex plate.

6.5.2 Transmission Inspection and Internal

Repair

Refer to the ZF Transmission Repair Manual PN- 5872 135 002 (JLG P/N 31200241) which can be obtained by calling your local JLG distributor.

If replacing the entire transmission, transfer the transmission temperature switch to the replacement transmission. The gear shift solenoids are included with a new transmission.

6.5.3 Transmission Installation

1. Install both rear transmission mounts on the transmission. Torque capscrews to 125-140 lb-ft (170-190 Nm).

2. Install two guide studs near the top of the bell housing holes.

3. Ensure there are no burrs on the flywheel mounting face and nose pilot bore. Clean the drive plate surface with solvent.

4. Ensure the bolts securing the flex plate to the torque converter are torqued to 26-29 lb-ft (35-39 Nm).

5. Use a hoist or overhead crane and sling attached to the lifting eye at the top of the transmission. Raise and position the transmission within the chassis. Make sure the engine flywheel and transmission flex plate hole patterns are aligned and in the same

orientation with one hole at 6 o’clock on the engine and the transmission.

6. Install the twelve bolts and washers and torque to 53 lb-ft (72 Nm). Remove the two alignment studs and install and torque the last two transmission mounting bolts.

7. Install the two rear transmission mounting bolts on the frame with two capscrews and two lockwashers. Apply Loctite

242 threadlock to the transmission mount

bolts and torque to 125-140 lb-ft (169-190 Nm).

8. Turn the engine over slowly by hand and align each of the four torque convertor diaphragm bolts through the access plug in the bell housing. Install them one at a time. DO NOT fully tighten until all of the capscrews and locknuts are in place. Torque to 26-29 lb-ft (35-39 Nm). Replace access plug.

9. Remove the hoist or overhead crane and sling.

10. Connect the transmission temperature switch connector and shift solenoid wiring harness connectors.

11. Secure the wiring harness to the transmission housing.

12. Connect the transmission oil cooler inlet and outlet hoses at the transmission.

13. Install the hydraulic pump. Refer to Section 8.7.3, “Pump Replacement.”

14. Install the transmission-to-axle drive shafts. Refer to Section 5.4.5, “Drive Shaft Installation.”

15. Install the air cleaner and tubing.

16. Clean the transmission oil filter mounting surface.

17. Apply a thin film of clean Mobilfluid 424

(ISO Grade 46) to the new transmission filter gasket. Install the new filter and torque to 20-25 lb-ft (27-34 Nm).

18. Transmission oil may be added through the oil fill tube. Remove the plug and add Mobilfluid 424

(ISO Grade 46). Check the oil level by taking intermittent dipstick readings as outlined in the appropriate Operation & Safety Manual. DO NOT overfill. Reinstall the oil fill tube plug and dipstick when finished.

19. Install the engine cover.

20. Connect the battery negative (-) cable at the battery.

21. Close and secure the engine cover.

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Transmission

6.5.4 After Transmission Service or Replacement

Refer to the ZF Transmission Repair Manual PN- 5872 135 002 (JLG P/N 31200241) which can be obtained by calling your local JLG distributor. In general:

1. Check the transmission oil level and add oil as required.

2. Install a new transmission filter.

3. Check the torque on the drive shaft yoke capscrews.

4. Wear suitable eye protection. When an overhauled or repaired transmission is installed, thoroughly clean the oil cooler lines to and from the transmission.

5. Drain and flush the entire system.

6. Disconnect and clean all transmission cooler hoses. When possible, remove transmission lines from the machine for cleaning.

7. Thoroughly clean transmission filter screens and cases, and replace transmission filter elements.

CAUTION

DO NOT exceed 165 psi (11,4 bar) when back flushing

the oil cooler. Applying too much pressure may damage the oil cooler/radiator.

MAP0690

10. Run the engine for two minutes at idle to help prime the torque converter and the transmission oil lines.

11. Recheck the level of the fluid in the transmission with the engine running at idle.

12. Add Mobilfluid 424 bring the fluid level up until it reaches the FULL mark on the dipstick. Recheck the oil level when it reaches operating temperature 180-200° F (83-94° C).

13. Recheck all drain plugs, lines, connections, etc., for leaks, and tighten where necessary.

(ISO Grade 46) as necessary to

8. Back flush the transmission oil cooler portion of the radiator or the oil cooler (located behind the radiator) with oil and compressed air until all foreign material is removed. Flushing in the direction of normal oil flow does not adequately clean the cooler. If needed, remove the radiator or oil cooler from the machine.

Note: DO NOT use flushing compounds for cleaning purposes.

9. Reassemble all components and fill the transmission with clean, fresh Mobilfluid 424 through the oil fill tube opening (4). Check the level by taking intermittent dipstick readings as outlined in the appropriate Operation & Safety Manual. DO NOT overfill. Reinstall the oil fill tube plug and dipstick when finished.

(ISO Grade 46)

6.6

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6.6 TROUBLESHOOTING

This section provides an easy reference guide covering the most common problems that may occur during operation of the transmission.

Note: Contact the JLG Service Department if internal transmission repair is required during the warranty period.

The transmission should be checked, serviced and repaired only by experienced service technicians who are aware of all safety instructions and particular component features.

6.6.1 Transmission Troubleshooting

Problem Cause Remedy

Transmission

1. Transmission will not engage or will not shift properly.

1. Oil level too high or low. 1. Fill transmission to correct level with Mobilfluid 424 (ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Transmission control lever not

functioning properly and/or a fault in the wiring harness.Transmission control lever not functioning properly and/or a fault in the wiring harness.

3. Transmission valve body

solenoids not functioning properly.

4. Pilot-operated shift valves not

operating properly.

5. Pump output pressure low. 5. Refer to Section 6.6.1,

2. Refer to Section 9.6, “Electrical System Schematics And Diagrams.”

3. Refer to Section 9.6, “Electrical System Schematics And Diagrams.”

4. Clean the valve spool and housing. Replace return spring as needed.

“Transmission Troubleshooting,” Problem 2. “Low or no pump flow or pressure.”

G10-55A & G12-55A AccuPlace

6. Clutch piston o-rings damaged. 6. Replace o-rings.

7. Clutch discs worn or damaged. 7. Replace clutch discs.

8. Coupling shafts or gear teeth damaged.

8. Replace couplings.

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Transmission

Problem Cause Remedy

2. Low or no pump flow or pressure.

1. Low oil level. 1. Fill transmission to correct level with Mobilfluid 424

(ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Transmission filled with incorrect

oil, or oil contaminated.

2. Drain transmission and fill to correct level with Mobilfluid 424 (ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

3. Pump suction pipe screen clogged.

3. Clean, repair and/or replace suction pipe.

4. Central shaft damaged. 4. Replace central shaft.

5. Pump worn or damaged. 5. Repair or replace pump assembly.

6. Electronic control function not

operating properly.

6. Check for DTC. Refer to Section

9.15.8, “Diagnostic Trouble Code (DTC) Table.” Refer to Section 9.15.2, “Debug Functionality.”

3. Low clutch pressure. 1. Incorrect oil level. 1. Fill transmission to correct level with Mobilfluid 424

(ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

6.8

2. Main pressure valve stuck open. 2. Clean the valve spool and housing.

3. Broken or worn coupling shaft or

3. Replace coupling and/or o-rings.

piston o-rings.

4. Pressure reducing valve stuck

open.

4. Clean the valve spool and housing.

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Problem Cause Remedy

4. Lack of power. 1. Park or service brake dragging. 1. Refer to Section 8.4, “Hydraulic

Circuits.”

5. Transmission overheating (oil above 120° C (248° F)).

2. Low engine rpm causes converter stall.

2. Adjust the engine rpm to specifications. Refer to Engine Service Manual.

3. Pump output pressure is low. 3. Refer to Section 6.6.1, “Transmission Troubleshooting,” Problem 2. “Low or no pump flow or pressure.”

4. Clutch discs worn or damaged. 4. Replace clutch discs.

5. Transmission overheating. 5. Refer to Section 6.6.1, “Transmission Troubleshooting,” Problem 5. “Transmission overheating (oil above 120° C (248° F)).”

1. Low oil level. 1. Fill transmission to correct level with Mobilfluid 424

(ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Clogged radiator. 2. Remove debris from the radiator.

3. Transmission filled with incorrect

oil, or oil contaminated.

3. Drain transmission and fill to correct level with Mobilfluid 424 (ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

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4. Excessive “roading.” 4. Stop and idle the engine.

5. Restriction in oil cooler hoses. 5. Replace cooler hoses.

6. Pump worn or damaged. 6. Repair or replace pump assembly.

7. Engine thermostat stuck. 7. Replace engine thermostat. Refer to Section 7.2.2, “Thermostat Replacement.”

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Problem Cause Remedy

6. Grinding or “clunking” noise from transmission.

1. Oil level too low. 1. Fill oil to correct level. Refer to Section 2.4, “Fluid and Lubricant Capacities.”

2. Transmission filled with incorrect

oil.

2. Drain transmission and fill to correct level with Mobilfluid 424 (ISO Grade 46). Refer to Section 2.4, “Fluid and Lubricant Capacities.”

3. Incorrect clutch engagement. 3. Refer to Section 9.11.8, “Transmission Solenoid Valves.”

4. Internal damage. 4. Repair or replace parts as needed.

5. Broken diaphragm (torque

convertor).

5. Replace diaphragm (torque convertor). Refer to Section

7.8.1, “Torque Convertor Diaphragm Removal.”

6. Loose diaphragm (torque

6. Tighten capscrews.

convertor) mounting capscrews.

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Problem Cause Remedy

Transmission

7. Oil leaking from transmission. 1. Oil leaking from vent (high oil

level).

2. Drain plug loose and/or o-rings damaged or missing.

3. Hose fittings loose. 3. Tighten fittings.

4. Oil leaking at valve bodies (possible valve body gaskets damaged or missing and/or mounting capscrews not tight).

5. Housing capscrews loose. 5. Tighten capscrews to 34 lb-ft

6. Oil leaking at pump (possible pump-to-housing o-rings missing or damaged, and/or pump mounting capscrews not tight).

7. Oil leaking at converter bell (possible converter leak and/or input shaft seal damage).

1. Remove drain plug and drain oil as needed, until oil is at correct level. Refer to Section 2.4, “Fluid and Lubricant Capacities.” Replace o-rings as needed and tighten plugs to 96 lb-ft (130 Nm).

2. Replace o-rings as needed and tighten plug to 26 lb-ft (35 Nm).

4. Replace gaskets and/or tighten capscrews to 7 lb-ft (9,5 Nm).

(46 Nm).

6. Replace o-rings and/or tighten capscrews to 85 lb-ft (115 Nm).

7. Replace converter and/or input shaft seal.

8. Oil leaking at output shaft (output shaft seal damaged).

9. Housing damaged. 9. Replace housing as needed.

8. Replace output shaft seal.

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Section 7

Engine

Contents

PARAGRAPH TITLE PAGE

7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2

7.1.1 Disclaimer and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2

7.1.2 Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3

7.1.3 Engine Serial Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4

7.1.4 Specifications and Maintenance Information . . . . . . . . . . . . . . . . . . . . . . 7.4

7.2 Engine Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4

7.2.1 Radiator Pressure Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4

7.2.2 Thermostat Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4

7.2.3 Radiator Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5

7.3 Engine Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6

7.4 Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6

7.4.1 Diesel Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6

7.4.2 Fuel Tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7

7.4.3 After Fuel System Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8

7.5 Engine Exhaust System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8

7.5.1 Exhaust System Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8

7.5.2 Exhaust System Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8

7.6 Air Cleaner Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.6.1 Air Cleaner Assembly Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.6.2 Air Cleaner Assembly Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.7 Engine Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.7.1 Engine Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9

7.7.2 Engine Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10

7.8 Torque Convertor Diaphragm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11

7.8.1 Torque Convertor Diaphragm Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11

7.8.2 Torque Convertor Diaphragm Installation . . . . . . . . . . . . . . . . . . . . . . . . . 7.11

7.9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.12

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7.1 INTRODUCTION

7.1.1 Disclaimer and Scope

These instructions are written for worldwide use. In territories where legal requirements govern engine smoke emission, noise, safety factors, etc., apply all instructions, data and dimensions provided herein in such a way that after maintenance, service and repair of the engine, engine operation does not violate local regulations.

Note: These instructions cover only the routine maintenance, removal, installation and troubleshooting of the engine. Refer to the local Engine Distributor and the applicable Engine Service Manual for assistance with comprehensive engine diagnosis, repair and component replacement. A gradual running-in (break-in) of a new engine is not necessary. Full load can be applied to a new engine as soon as the engine is put into service and the coolant temperature is at least 140° F (60° C). Extended light-load operation during the early life of the engine is not recommended. DO NOT run the engine at high, no-load speeds. DO NOT apply an overload to the engine.

7.2

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7.1.2 Component Terminology

To understand the safety, operation and maintenance information presented in this section, it is necessary that the operator/mechanic be familiar with the names and locations of the engine components. The following illustration identifies the components that are referred to throughout this section.

THERMOSTAT

FUEL FILTER

Engine

OIL FILTER

STARTER

MAL0260

ALTERNATOR

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7.1.3 Engine Serial Number

The Perkins 1104D serial number is stamped on top of the engine. Information contained in the serial number is required in correspondence with the engine manufacturer.

7.1.4 Specifications and Maintenance Information

For engine, coolant and oil specifications, and maintenance information, refer to Section 2, “General Information and Specifications.”

Detailed Perkins engine service instructions (covering disassembly, inspection, internal repair, assembly, adjustment and troubleshooting information) are provided in the appropriate Perkins engine service manual.

7.2 ENGINE COOLING SYSTEM

7.2.1 Radiator Pressure Cap

For a 210° F (99° C) system, use a 13 psi (90 kPa) radiator cap. An incorrect or malfunctioning cap can result in the loss of coolant and a hot-running engine.

a. Thermostat Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

5. Slowly turn the radiator cap to the first stop and allow any pressure to escape. Remove the radiator cap.

6. Place a funnel at the base of the radiator to channel the drained coolant into the container. Loosen the drain plug and slowly remove to allow the coolant to drain. Transfer the coolant into a properly labeled container. Dispose of properly if coolant needs to be replaced. Replace the radiator drain plug.

7.2.2 Thermostat Replacement

Before considering thermostat replacement, check the coolant level, fan belt tension and instrument cluster temperature indicator.

• If the engine seems to take a long time to warm up, the thermostat may be stuck in the open position and requires replacement.

• If the engine runs hot, check the temperature of the upper radiator hose.

• If the hose is not hot, the thermostat may be stuck in the closed position.

• If the engine has overheated, performance may suffer, indicating other damage including a leaking cylinder head gasket, cracked cylinder head or block, and/or other internal engine damage.

MY2750

7. Disconnect the Engine Water Temperature Sender.

8. Remove the two capscrews securing the thermostat housing (1) to the engine.

9. Remove the thermostat housing, old gasket and thermostat. Clean all gasket surfaces. DO NOT let any debris into the thermostat opening.

Note: ALWAYS use the correct thermostat and install a new gasket. NEVER operate the engine without a thermostat, or engine damage will result.

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b. Thermostat Installation

1. Install the engine thermostat, thermostat gasket and thermostat housing. Secure with the two capscrews.

2. Connect the Engine Water Temperature sender.

3. Connect the battery negative (-) cable to the battery negative (-) terminal.

4. Open the radiator cap, and fill the radiator completely with a 50/50 mixture of ethylene glycol and water. Replace and tighten the radiator cap. Add coolant to the overflow bottle until the bottle is 1/4 to 1/2 full. This overfilling will compensate for any air trapped in the cooling system.

5. Run the engine to operating temperature. Visually check for leaks with the engine running. Check the coolant level in the overflow bottle and fill, or drain, as necessary.

7.2.3 Radiator Replacement

Before considering radiator replacement for other than obvious damage, conduct a cooling system pressure test, check the coolant specific gravity, coolant level, fan belt tension and dash panel temperature indicator.

• If the engine runs hot, check the temperature of the upper radiator hose.

• If the hose is not hot, the thermostat may be stuck in the closed position.

• If the engine has overheated, performance may suffer, indicating other damage including a leaking cylinder head gasket, cracked cylinder head or block, and/or other internal engine damage.

7. Place a funnel at the base of the radiator to channel the drained coolant into a container. Loosen the drain cock and slowly remove to allow the coolant to drain. Transfer the coolant into a properly labeled container. Dispose of properly if coolant needs to be replaced. Tighten the radiator drain cock.

8. Label, disconnect and cap the hose attached to the coolant recovery tank. Remove the coolant recovery tank.

9. Loosen the clamps on the hoses attached to the radiator. Work the hoses off the radiator. Position the hoses out of the way to allow radiator removal, or remove the hoses from the engine. Inspect the hoses, and replace if necessary.

10. Loosen the clamps on the hoses attached to the oil cooler. Work the hoses off the oil cooler. Position the hoses out of the way to allow radiator removal, or remove the hoses from the engine. Inspect the hoses, and replace if necessary.

11. Remove the radiator fan shroud.

12. Remove the nuts and washers from the radiator and oil cooler mounts.

13. Carefully lift the radiator and oil cooler out of the engine compartment.

Note: If more clearance is needed to remove the radiator, the engine fan may be removed for easier access.

a. Radiator Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

5. Slowly turn the radiator cap to the first stop and allow any pressure to escape. Remove the radiator cap.

6. Place a suitable container beneath the radiator drain.

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b. Radiator Installation

1. Install the isolator mounts to the bottom of the radiator. Place the radiator in the engine compartment at its original orientation. Secure with the previously used hardware.

Note: Ensure there is adequate clearance between the radiator and the engine fan.

2. If necessary, install the engine fan.

3. Install the radiator fan shroud.

4. Uncap and connect the previously labeled hoses to the radiator and oil cooler.

5. Install the coolant recovery tank. Uncap and connect the previously removed hose.

6. Open the radiator cap and fill the radiator completely with a 50/50 mixture of ethylene glycol and water. Replace and tighten the radiator cap. Refer to Section 2.4, “Fluid and Lubricant Capacities,” for proper capacities.

7. Connect the battery negative (-) cable to the battery negative (-) terminal.

8. Run the engine to operating temperature. Visually check for leaks with the engine running. Check the coolant level in the overflow bottle and fill, or drain, as necessary.

Note: Due to the precise tolerances of diesel injection systems, keep the fuel clean, and free of dirt and water. Dirt and water in the fuel system can cause severe damage to both the injection pump and the injection nozzles. Use ASTM #2 diesel fuel with a minimum Cetane rating of 40. #2 diesel fuel gives the best economy and performance under most operating conditions. Fuels with Cetane numbers higher than 40 may be needed in high altitudes or extremely low ambient temperatures to help prevent misfiring and excessive smoking.

Inform the owner/operator of the machine to use #2 diesel fuel, unless ambient temperatures are below 32° F (0° C). When temperatures are below 32° F (0° C), a blend of #1 diesel and #2 diesel fuels (known as “winterized” #2 diesel) may be used.

Note: #1 diesel fuel may be used, however, fuel economy will be reduced.

Use a low-sulfur content fuel with a cloud point (the temperature at which wax crystals form in diesel fuel) at least 10° below the lowest expected fuel temperature. The viscosity of the fuel must be kept above

1.3 centistrokes to provide adequate fuel system lubrication.

7.3 ENGINE ELECTRICAL SYSTEM

The engine electrical system, including the starter, alternator and primary wiring, is described in Section 9.6, “Electrical System Schematics And Diagrams.”

7.4 FUEL SYSTEM

7.4.1 Diesel Fuel

Fuel represents a major portion of machine operating costs and therefore must be used efficiently. ALWAYS use a premium brand of high-quality, clean diesel fuel. Low cost, inferior fuel can lead to poor performance and expensive engine repair.

Note: Use only diesel fuel designed for diesel engines. Some heating fuels contain harmful chemicals that can seriously affect engine efficiency and performance.

MAP0180

7.6

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7.4.2 Fuel Tank

Note: The fuel tank is a one piece unit. It is located on the rear of the cab. If it is determined that the fuel tank must be removed, the fuel must be drained before tank removal. Always dispose of fuel properly.

a. Fuel Tank Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

Note: If replacing the tank, remove all internal and external components from the old tank, and retain for use on the replacement tank.

Note: Have a dry chemical (Class B) fire extinguisher near the work area.

5. Remove fuel tank drain plug, and drain fuel into an approved and suitable container. Dispose of fuel properly.

6. Label, disconnect and cap the fuel lines from the bottom of the fuel tank.

7. Disconnect the fuel gauge harness.

8. Remove screws securing fuel sender to the tank. Remove fuel sender from tank.

9. Remove the bolts on the fuel tank hold down bar.

10. Lift the empty fuel tank from the rear of the cab.

b. Disassembly

The fuel tank is a one-piece unit and cannot be disassembled. The fuel level indicator can be removed and reused on the new replacement tank. Dispose of the old tank according to local regulations concerning hazardous materials disposal.

c. Cleaning and Drying

If contaminated fuel or foreign material is in the tank, the tank can usually be cleaned.

Note: If a leak is suspected in the fuel tank, contact JLG Service Department.

To clean the fuel tank:

1. Have a dry chemical (Class B) fire extinguisher near the work area.

2. Remove the fuel or oil tank drain plug, and safely drain any fuel into a suitable container. Dispose of fuel properly.

3. Clean the fuel tank with a high-pressure washer, or flush the tank with hot water for five minutes and drain the water. Dispose of contaminated water properly.

4. Add a diesel fuel emulsifying agent to the tank. Refer to the manufacturer’s instructions for the correct emulsifying agent-to-water mixture ratio. Refill the tank with water, and agitate the mixture for 10 minutes. Drain the tank completely. Dispose of contaminated water properly.

5. Refill the fuel tank with water until it overflows. Completely flush the tank with water. Empty the fuel tank, and allow it to dry completely.

d. Assembly

The fuel level indicator can be removed and reused on the new replacement tank. Dispose of the old tank according to local regulations concerning hazardous materials disposal regulations.

e. Inspection

Note: If a leak is suspected in the fuel tank, contact the JLG Service Department.

1. Inspect the fuel tank thoroughly for any cracks, slices, leaks or other damage.

2. With the fuel tank removed from the machine, plug all openings except one elbow fitting. Install the elbow fitting, and apply approximately 1-1.5 psi (7-10 kPa) of air pressure through the elbow. Check the reservoir for leaks by applying a soap solution to the exterior and look for bubbles to appear at the cracked or damaged area.

f. Fuel Tank Installation

1. Set fuel tank in its original orientation at the rear of the cab.

2. Install the fuel tank hold down bar.

3. Install the fuel sender with new gasket into the fuel tank and secure with screws. DO NOT overtighten.

4. Connect the previously labeled fuel hoses to their appropriate locations. Secure with clamps.

5. Connect the fuel gauge harness.

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6. Fill the fuel tank according to specifications. Refer to Section 2.4, “Fluid and Lubricant Capacities.”

7. Check fuel tank for leaks.

8. Connect the battery negative (-) cable to the battery negative (-) terminal.

9. Close and secure the engine cover.

7.4.3 After Fuel System Service

1. Drain and flush the fuel tank if it was contaminated.

2. Vent air from the fuel system in accordance with the instructions found in the appropriate Operation & Safety Manual.

3. Fill the fuel tank with fresh, clean diesel fuel as required.

7.5 ENGINE EXHAUST SYSTEM

7.5.1 Exhaust System Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

5. Remove the heat shield attached to the engine.

6. Loosen and remove the clamp from the exhaust pipe at the exhaust manifold.

7. Disconnect and remove the clamp attaching the exhaust pipe to the frame.

8. Disconnect and remove the clamp connecting the muffler and the exhaust pipe.

9. Disconnect and remove the clamp connecting the tail pipe to the muffler and remove the tail pipe.

10. Loosen and remove the bolts at the front and rear of the muffler, remove the muffler.

7.5.2 Exhaust System Installation

Note: Keep all clamps loosened until entire exhaust system is in place.

MAP0190

1. Install the exhaust pipe with a new seal to the exhaust manifold.

Note: Replace the nuts and the exhaust manifold studs if damaged.

2. Install the exhaust pipe clamp.

3. Install the muffler to the exhaust pipe and bolt the muffler to the frame.

4. Install the clamp securing the muffler to the exhaust pipe.

5. Install the clamp securing the muffler to the tail pipe.

6. Adjust the muffler, exhaust and tail pipes for proper clearance then tighten all clamps.

7. Install the heat shield attached to the engine.

8. Connect the battery negative (-) cable to the battery negative (-) terminal.

9. Start engine and check for exhaust leaks at all exhaust connections. Adjust or repair as needed.

10. Close and secure the engine cover.

7.8

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7.6 AIR CLEANER ASSEMBLY

CAUTION

NEVER run the engine with only the inner safety

element installed.

Note: Refer to the appropriate Operation & Safety Manual for your machine for the correct element change procedure.

7.6.1 Air Cleaner Assembly Removal

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Remove the battery negative (-) cable from the battery negative (-) terminal.

5. Remove the clamp securing the air intake elbow to the air cleaner assembly. Lift the air intake elbow off the air cleaner.

6. Remove the capscrews and nuts securing the air cleaner mounting bracket to the air cleaner mounting plate. Remove the air cleaner assembly.

7.7 ENGINE REPLACEMENT

7.7.1 Engine Removal

Note: The radiator and oil cooler must be removed from the machine before engine removal. Refer to Section

7.2, “Engine Cooling System.” Several additional components must be removed before engine removal. They will be addressed in the following procedures.

2. Place a Do Not Operate Tag on both the ignition key switch and steering wheel, stating that the machine should not be operated.

3. Open the engine cover. Allow the system fluids to cool.

4. Disconnect the (+) positive and (-) negative battery cables and remove the battery.

5. Remove the engine cover. Mark the position of the cover to help with cover adjustment when being reinstalled.

6. Remove the oil pan cover underneath the engine compartment.

7. Drain and remove the radiator assembly. Refer to Section 7.2.3, “Radiator Replacement.”

8. Remove the heater hoses attached to the engine (if equipped).

7.6.2 Air Cleaner Assembly Installation

Note: Apply Loctite® 242 threadlock to the capscrew threads before installation.

1. With the air cleaner assembly attached, install the air cleaner mounting bracket using capscrews and nuts.

2. Place the loosened clamps over the air outlet elbow and install elbow on the air cleaner assembly.

3. Adjust and tighten both clamps to 30 lb-in (3 Nm) before starting the machine.

4. Connect the battery negative (-) cable to the battery negative (-) terminal.

5. Close and secure the engine cover.

G10-55A & G12-55A AccuPlace

Note: The engine harness is routed and attached to the engine using hold-down clamps and plastic wire ties at various places on the engine. Before removing engine, ensure that the harness has been completely separated (disconnected) from the engine. Move the harness clear of the engine, and with the help of an observer, ensure that the engine clears the harness during removal.

9. Label and disconnect all electrical wire connections on the engine.

10. Label and disconnect all electrical wire connections on the power distribution bracket.

11. Remove the power distribution bracket.

12. Disconnect and cap the fuel inlet line at the fuel filter head.

13. Disconnect and cap the fuel return line from the fuel filter head.

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MY1030

14. Remove the exhaust pipe from the exhaust manifold. Refer to Section 7.5.1, “Exhaust System Removal.”

15. Loosen the clamps on the sleeve reducer at the engine and on the air suction pipe.

16. Remove the air cleaner assembly. Refer to Section

7.6.1, “Air Cleaner Assembly Removal.”

17. Remove the access plug (1) from bottom of the engine bell housing. This will allow access to remove the bolts holding the torque convertor diaphragm to the engine flywheel.

18. Turn the engine over slowly by hand and align each of the four torque convertor diaphragm bolts to be accessed. Remove them one at a time.

19. Secure the engine with a lifting strap or chain from the appropriate lifting points. Use a suitable hoist or overhead crane.

20. Place a support or jack under the transmission to hold the transmission in place while engine is being removed.

21. Remove the bolts and washer securing the engine mounts.

22. Remove the ten bolts holding the transmission to the engine. Slightly lift and pull the engine out of the machine. Have an assistant ensure that the engine clears all frame components during removal.

23. Place engine on a flat, level surface.

7.7.2 Engine Installation

1. Attach a lifting chain to the front and rear engine lift brackets, and lift engine clear of the ground.

Note: Apply Loctite mount bracket capscrew threads before installation.

2. Install two guide studs in the bell housing holes.

3. Lift the engine and slowly push and lower into the engine bay. Have an assistant ensure that the engine clears the frame, hose and harness components during engine installation. Position engine brackets over the front frame mounts.

4. Push the engine towards the transmission aligning the guide studs and the torque convertor shaft with the corresponding holes.

5. Push the engine against the transmission and install eight of the ten bolts and washers. Remove both guide studs and replace with the remaining two bolts and washers. Torque bolts to 53-58 lb-ft (72-79 Nm).

6. Remove the support from under the transmission and lower the engine the remainder of the way onto the frame. Align the motor mount holes and install the bolts. Apply Loctite mount bolts and torque to 125-140 lb-ft (169-190 Nm).

7. Turn the engine over slowly by hand and align each of the four torque convertor diaphragm bolts through the access plug in the bell housing. Install them one at a time. DO NOT fully tighten until all of the capscrews and locknuts are in place. Torque to 26-39 lb-ft (35-59 Nm). Replace access plug.

8. Install the exhaust pipe. Refer to Section 7.5.2, “Exhaust System Installation.”

9. Install the complete air cleaner assembly. Refer to Section 7.6.2, “Air Cleaner Assembly Installation.”

10. Connect the fuel inlet line to the fuel filter head.

11. Connect the fuel return line to the fuel filter head.

12. Install the Power Distribution bracket.

13. Connect all the previously labeled electrical wire connections on the Power Distribution bracket.

14. Connect all the previously labeled electrical wire connections on the engine.

15. Install both heater hoses to the engine and tighten clamps (if equipped).

16. Install the complete radiator assembly. Refer to Section 7.2.3, “Radiator Replacement.”

17. Install the engine cover and adjust.

242 threadlock to the engine

242 threadlock to the motor

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Engine

18. Install the battery and connect the (+) positive and (-) negative cables.

19. Check that all hydraulic system, electrical system, cooling system, fuel system and exhaust system connections are correct and connected tightly.

20. From within the cab, lightly depress the throttle pedal to full-throttle position. As needed, adjust the limitstop screw until it touches the pedal bracket.

Note: Have an assistant stand by with a Class B fire extinguisher.

21. Start the engine and run to normal operating temperature then shut off the engine. While the engine is cooling, check for leaks.

22. Allow the engine to cool. Check the radiator coolant level, and top off with a 50/50 mixture of ethylene glycol and water. Replace the radiator cap.

23. Check for leaks from the engine, main hydraulic pump and lines, transmission, hydraulic reservoir and fuel tank. Check the levels of all fluids and lubricants. Fill as required.

Note: During the full throttle check:

7.8 TORQUE CONVERTOR DIAPHRAGM

7.8.1 Torque Convertor Diaphragm Removal

Note: In order to remove the engine drive plates, the engine and transmission must be separated.

2. Refer to Section 6.5.1, “Transmission Removal,” or Section 7.7.1, “Engine Removal.”

•DO NOT operate any hydraulic function.

•DO NOT steer or apply any pressure to the steering

wheel.

• Keep the transmission in (N) NEUTRAL.

24. Obtain and connect an appropriate engine analyzer or tachometer. Check the engine rpm at full throttle.

25. Purge the hydraulic system of air by operating all boom functions through their entire range of motion several times. Check the hydraulic oil level.

26. Check for proper operation of all components.

27. Turn the engine OFF.

28. Install the oil pan cover underneath the engine compartment.

29. Close and secure the engine cover.

3. Remove the four bolts holding the diaphragms to the flywheel.

4. With the drive plates and torque converter removed, loosen and remove the four bolts (2) and eight lock washers holding the two diaphragms (3) to the torque converter (4).

5. Replace both diaphragms if damaged.

7.8.2 Torque Convertor Diaphragm Installation

1. Install the two new diaphragms on the torque converter and install the four bolts with lock washers.

2. Mount the diaphragm/converter assembly to the transmission.

3. Refer to Section 6.5.3, “Transmission Installation,” or Section 7.7.2, “Engine Installation,” for the remainder of the installation.

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7.9 TROUBLESHOOTING

Trouble Possible Causes (see key, below)

Low Cranking Power

Will Not Start

Difficult Starting

Lack of Power

Misfiring

Excessive Fuel Consumption

Black Exhaust

Blue/White Exhaust

Low Oil Pressure

Knocking

Erratic Running

Vibration

High Oil Pressure

Overheating

Excessive Crankcase Pressure

Poor Compression

Starts and Stops

1, 2, 3, 4

5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 31, 32, 33

5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 24, 29, 31, 32, 33, 61, 63

8, 9, 10, 11, 12, 13, 14, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 31, 32, 33, 61, 63

8, 9, 10, 12, 13, 14, 16, 18, 19, 20, 25, 26, 28, 29, 30, 32

11, 13, 14, 16, 18, 19, 20, 22, 23, 24, 25, 27, 28, 29, 31, 32, 33, 63

11, 13, 14, 16, 18, 19, 20, 22, 24, 25, 27, 28, 29, 31, 32, 33, 61, 63

4, 16, 18, 19, 20, 25, 27, 31, 33, 34, 35, 45, 56, 62

4, 36, 37, 38, 39, 40, 42, 43, 44, 58

9, 14, 16, 18, 19, 22, 26, 28, 29, 31, 33, 35, 36, 45, 46, 59

7, 8, 9, 10, 11, 12, 13, 14, 16, 20, 21, 23, 26, 28, 29, 30, 33, 35, 45, 59

13, 14, 20, 23, 25, 26, 29, 30, 33, 45, 47, 48, 49

4, 38, 41

11, 13, 14, 16, 18, 19, 24, 25, 45, 50, 51, 52, 53, 54, 57

25, 31, 33, 34, 45, 55, 60

11, 19, 25, 28, 29, 31, 32, 33, 34, 46, 59

10, 11, 12

Key to Possible Causes

1. Battery charge low

2. Bad electrical connection

3. Faulty starter motor

4. Incorrect grade of lubricating oil

5. Low cranking speed

6. Fuel tank empty

7. Faulty stop control operation

8. Fuel inlet restricted

9. Faulty fuel lift pump

10. Clogged fuel filter

11. Restricted air cleaner

12. Air in fuel system

13. Faulty fuel injection pump

14. Faulty fuel injectors or incorrect type

15. Incorrect use of cold start equipment

16. Faulty cold start equipment

17. Broken fuel injection pump drive

18. Incorrect fuel pump timing

19. Incorrect valve timing

20. Poor compression

21. Blocked fuel tank vent

22. Incorrect grade of fuel

23. Sticking throttle or restricted movement

24. Exhaust pipe restriction

25. Leaking cylinder head gasket

26. Overheating

27. Cold running

28. Incorrect tappet adjustment

29. Sticking valves

30. Incorrect high pressure pipes

31. Worn cylinder bores

32. Pitted valves and seats

33. Broken, worn or sticking piston ring(s)

34. Worn valve stems and guides

35. Restricted air cleaner

36. Worn or damaged bearings

37. Insufficient oil in sump

38. Inaccurate gauge

39. Oil pump worn

40. Pressure relief valve sticking open

41. Pressure relief valve sticking closed

42. Broken relief valve spring

43. Faulty suction pipe

44. Restricted oil filter

45. Piston seizure/pick up

46. Incorrect piston height

47. Damaged fan

48. Faulty engine mounting

49. Incorrectly aligned flywheel housing or incorrectly aligned flywheel

50. Faulty thermostat

51. Restriction in water jacket

52. Loose fan belt

53. Restricted radiator

54. Faulty water pump

55. Restricted breather pipe

56. Damaged valve stem oil deflectors (if fitted)

57. Coolant level too low

58. Blocked sump strainer

59. Broken valve spring

60. Exhauster or vacuum pipe leak

61. Turbo impeller damaged or dirty

62. Turbo lubricating oil seal leak

63. Induction system leaks

7.12

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Section 8

Hydraulic System

Contents

PARAGRAPH TITLE PAGE

8.1 Hydraulic Component Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2

8.2 Safety Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3

8.3 Hydraulic Pressure Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4

8.3.1 Pressure Checks and Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4

8.4 Hydraulic Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5

8.4.1 Hydraulic Pressures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5

8.5 Hydraulic System Schematics and Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7

8.5.1 Chassis Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7

8.5.2 Boom Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8

8.5.3 Hydraulic Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.9

8.6 Hydraulic Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12

8.6.1 Hydraulic Oil Reservoir Draining. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12

8.6.2 Hydraulic Oil Reservoir Filling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12

8.6.3 Hydraulic Oil Reservoir Removal/Installation . . . . . . . . . . . . . . . . . . . . . . 8.12

8.7 Engine Implement Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13

8.7.1 Pump Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13

8.7.2 Pump Failure Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13

8.7.3 Pump Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13

8.8 Control Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.14

8.8.1 Lift Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.14

8.8.2 ISP Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.15

8.8.3 Stabilizer Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.16

8.8.4 Auxiliary Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.17

8.8.5 Telescope Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.17

8.8.6 Tilt Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.18

8.8.7 Service Brake Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.19

8.8.8 Brake Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.19

8.8.9 Steering Orbitrol Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.20

8.8.10 Steer Select Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.20

8.8.11 Valve Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.22

8.9 Hydraulic Piston Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.22

8.9.1 Accumulator Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.22

8.9.2 Accumulator Pre-Charge & Check Procedure . . . . . . . . . . . . . . . . . . . . . 8.23

8.10 Hydraulic Cylinders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.24

8.10.1 General Cylinder Removal Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . 8.24

8.10.2 Cylinder Pressure Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.26

8.10.3 Steering Cylinders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.26

8.10.4 Cylinder Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.27

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8.1 HYDRAULIC COMPONENT TERMINOLOGY

To understand the safety, operation and service information presented in this section, it is necessary that the operator/mechanic be familiar with the name and location of the hydraulic components of the machine. The following illustration identifies the components that are referred to throughout this section.

AUXILIARY VALVE &

TILT VALV E

TILT CYLINDER

OUTRIGGER

CYLINDER

EXTEND/RETRACT

CYLINDER

(engine compar tment)

STABILIZER

VALVE

SWAY CYLINDER

(behind tire)

STEERING SELECT

ISP VALVE

VALV E

HYDRAULIC OIL

RESERVOIR

HYDRAULIC MANIFOLD

(engine compartment)

LIFT/LOWER

CYLINDER(S)

HYDRAULIC PISTON

ACCUMULATOR

LIFT VALVE

MAP0330

STABILIZER

CYLINDER

(behind tire)

8.2

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8.2 SAFETY INFORMATION

WARNING

DO NOT service the machine without following all

safety precautions as outlined in Section 1, “Safety Practices,” of this manual. Failure to follow the safety practices could result in death or serious injury.

Petroleum-based hydraulic fluids are used in this machine. The temperature of hydraulic fluid increases during the operation of various hydraulic functions. A heated petroleum-based hydraulic fluid presents a fire hazard, especially when an ignition source is present. Hydraulic fluid has a flash point that ranges from 300-600° F (150-318° C) and an auto-ignition temperature of 500-750° F (262-402° C).

Accordingly, periodically inspect all hydraulic system components, hoses, tubes, lines, fittings, etc. Carefully examine any deterioration and determine whether any further use of the component would constitute a hazard. If in doubt, replace the component.

Operate the hydraulic controls after the engine has stopped to relieve trapped pressure.

Note: Residual pressure may remain in hydraulic cylinders, hoses, valve bodies, components, etc. If the hydraulic lines going to or coming from a component are taut, slowly

and cautiously relieve (“bleed off”) pressure.

Whenever you disconnect a hydraulic line, coupler, fitting or other component, slowly involved. A hissing sound or slow seepage of hydraulic fluid may occur in most cases. After the hissing sound has ceased, continue removing the part. Any escaping oil should be directed into an appropriate container. Cap or otherwise block off the part to prevent further fluid seepage.

Hydraulic system maintenance will, at times, require that the engine be operated. Always follow safety precautions.

A major cause of hydraulic component failure is contamination. Keeping the hydraulic fluid as clean as possible will help avoid downtime and repairs. Sand, grit and other contaminants can damage the finely machined surfaces within hydraulic components. If operating in an exceptionally dirty environment, change filters and inspect the fluid more often. When servicing the system, cap or plug hydraulic fittings, hoses and tube assemblies. Plug all cylinder ports, valves and the hydraulic reservoir, and pump openings until installation occurs. Protect threads from contamination and damage.

Some hydraulic functions are actuated by interfacing with electrical system components (switches, solenoids and sensors). When the hydraulic system is not functioning properly, check the electrical aspect of the malfunctioning circuit also. Refer to Section 9.6, “Electrical System Schematics And Diagrams,” in this manual.

and cautiously loosen the part

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8.3 HYDRAULIC PRESSURE DIAGNOSIS

JLG Parts Department has a kit available to use for hydraulic system maintenance and troubleshooting: the JLG Pressure Test Kit. The kit is contained in a durable polyethylene carrying case for demanding field service conditions.

Pressure Test Kit

The hydraulic pressure test kit is used to pressure test the various hydraulic components in the hydraulic system. The kit includes:

• Gauges for testing high and low pressure circuits

• Fittings, couplers and hoses

MZ1460

Contact JLG Parts Department at 717-485-6472 for ordering information.

Part

Number

70000652 Hydraulic Pressure

70000101 Digital Hydraulic

Description Approximate

Weight

10 lbs. Consult Factory

Te st K it

7 lbs. Consult Factory

Pressure Test Kit

Price and

Availability

8.3.1 Pressure Checks and Adjustments

When diagnosing trouble in the hydraulic system, use the hydraulic testing information in Section 8.4.1, “Hydraulic Pressures.”

In general, follow the steps below whenever conducting pressure checks and performing adjustments:

1. Park the machine on a firm, level surface. Engage the park brake, place the travel select lever in (N) NEUTRAL, level the boom and turn the engine OFF.

2. The test ports are located on the hydraulic manifold in the engine compartment. Install a pressure gauge capable of measuring at least 10% more pressure than that which the circuit being checked operates under.

3. Start the engine. Operate machine functions several times to allow hydraulic oil to reach operating temperature. The hydraulic oil temperature should be between 100-120° F (38-49° C). If a temperature gauge or thermometer is unavailable, the hydraulic oil reservoir should be warm to the touch.

4. Refer to Section 8.4.1, “Hydraulic Pressures,” for testing procedures.

5. Fully depress the accelerator pedal if required. Place and hold the joystick in the position needed to operate the particular machine function being checked. Continue holding the joystick in position until pressure readings are taken.

6. Check the pressure gauge reading. It should read as specified in the Pressure Range column of the charts found in Section 8.4.1, “Hydraulic Pressures.” If the reading is not as specified, turn the engine OFF and check other components in the system. Verify that all related hydraulic components and electrical switches, sensors, solenoids, etc. are operating correctly.

7. Adjust the relief valve by turning the adjustment screw. Turning clockwise will increase the pressure; turning the screw counterclockwise will decrease the pressure.

8. Start the engine and check the pressure again. Turn the engine OFF. If there is pressure reading in the gauge, bleed it off then disconnect or remove the pressure gauge from the machine.

8.4

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8.4 HYDRAULIC CIRCUITS

This section covers the hydraulic circuits and includes listings for all hydraulic function pressures, where and how to check those pressures and a hydraulic schematic.

Electrical and hydraulic functions are often related. Verify that the electrical components of the circuit are functioning properly whenever troubleshooting the hydraulic circuit.

Always check the following before beginning to troubleshoot a circuit that is not functioning correctly.

1. Check the hydraulic oil level in the reservoir. Oil level should be to the middle of the sight glass with all cylinders retracted.

2. Check hoses, tubes, fittings and other hydraulic components for leaks, bends, kinks, interference, etc.

3. Check for air in the hydraulic system. Erratic machine performance and/or spongy cylinder operation are signs of air in the hydraulic system.

If air in the hydraulic system is suspected, you will hear air leakage when hydraulic fittings are loosened and see air bubbles in the hydraulic fluid.

Loose fittings, faulty o-rings or seals, trapped oil, leaks, system opened for service, etc., can cause air in the system. Determine what is causing air to enter the system and correct it. Bleed air from the system.

machine off, install the safety cap and remove the gauge from the test port.

4. If the proper pressure cannot be set, use the accompanying hydraulic schematic and/or the electrical schematic to help troubleshoot and correct the problem.

8.4.1 Hydraulic Pressures

a. Checking Pressure

1. Start the machine and warm the hydraulic system to operating temperature.

2. Shut off the machine and install a digital or a 5000 psi (345 bar) gauge to the appropriate test port on the hydraulic manifold.

3. Start the machine, run the engine at idle and bottom the appropriate hydraulic function. Refer to Section

8.4.1, c. “Pressure Specifications,” for the correct pressure rating.

b. Adjusting Hydraulic Pressure

1. Shut the machine off. Remove the cap on the relief (if necessary).

2. Start the machine and loosen the jam nut on the relief. Turn the relief clockwise to increase pressure or counter-clockwise to decrease pressure. Set to the correct pressure.

3. Tighten the jam nut and recheck the pressure at full throttle. If the reading is within specification, shut the

MAP0550

5. The Load Sense (LS) Pressure Adjustment Plug (1) adjusts the swashplate angle (and therefore, the system flow) to maintain a constant pressure delta (or Margin Pressure) across an external control valve.

6. The Pressure Compensator (PC) Adjustment Plug (2) maintains the system pressure in the hydraulic circuit at or below the PC setting by varying the output flow of the pump if needed. The pump remains at maximum displacement until the LS control has enough margin pressure for the flow command, or the system pressure exceeds the PC setting.

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c. Pressure Specifications

Hydraulic Circuit Test Port Adjustment

Location

System Relief G1 Refer to Section

Function Used to

Pressure Range

Test

Tilt Forward 3550-3700 psi

8.4.1, “Hydraulic Pressures.”

Priority Relief

GLS 1 Steering 2950-3050 psi

(Steering)

Brake BV1 2 Steering 1050-1150 psi

Park Brake PBG Not Adjustable No Function 450-550 psi

Note: Bring engine to high idle and bottom out designated function to test the hydraulic pressures.

GLS

PBG

(245-255 Bar)

(203-210 Bar)

(72-79 Bar)

(31-38 Bar)

8.6

BV1

MAP041

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8.5 HYDRAULIC SYSTEM SCHEMATICS AND DIAGRAMS

8.5.1 Chassis Schematic

Hydraulic System

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Hydraulic System

8.5.2 Boom Schematic

8.8

MAP0320 D

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8.5.3 Hydraulic Diagram

Hydraulic System

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Hydraulic System

8.5.3 Hydraulic Diagram (Continued)

8.10

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Specifications and Main Features

Frequently Asked Questions

User Manual

SECTION CONTENTS

1.1 INTRODUCTION

1.2 DISCLAIMER

1.3 OPERATION & SAFETY MANUAL

1.4 DO NOT OPERATE TAGS

1.5 SAFETY INFORMATION

1.5.1 Safety Alert System and Signal Words

1.6 SAFETY INSTRUCTIONS

1.6.1 Personal Hazards

1.6.2 Equipment Hazards

1.6.3 General Hazards

1.6.4 Operational Hazards

1.7 SAFETY DECALS

2.1 REPLACEMENT PARTS AND WARRANTY INFORMATION

2.2 TORQUES

2.2.1 ASTM Fastener Torque Chart (English)

2.2.2 ASTM Fastener Torque Chart (Metric)

2.2.3 Metric Fastener Torque Chart

2.3 SPECIFICATIONS

2.3.1 Travel Speeds

2.3.2 Electrical System

2.3.3 Engine Performance Specifications

2.3.4 Tires

2.4 FLUID AND LUBRICANT CAPACITIES

2.5 SERVICE AND MAINTENANCE SCHEDULES

2.5.1 10, 1st 100 & 50 Hour

2.5.2 250, 500, 1000 & 1500 Hour

2.6 LUBRICATION SCHEDULES

3.1 BOOM SYSTEM COMPONENT TERMINOLOGY

3.2 BOOM SYSTEM - FOUR SECTION

3.2.1 Boom System Operation

3.3 BOOM ASSEMBLY MAINTENANCE

3.3.1 Boom Removal

3.3.2 Second, Third & Fourth Boom Section Removal

3.3.3 Third & Fourth Boom Section Removal

3.3.4 Fourth Boom Section Removal

3.3.5 Fourth Boom Section Installation

3.3.7 Second Boom Section Installation

3.3.8 Boom Installation

3.4.1 Boom Chain Inspection

3.4.2 Inspection Guidelines

3.4.3 Expose Chains for Inspection

3.4.4 Chain Lubrication

3.4.5 Retract Chain Removal

3.4.6 Retract Chain Installation

3.4.7 Extend Chain Removal

3.4.8 Extend Chain Installation

3.5 BOOM SECTION SEPARATION ADJUSTMENT

3.6 HYDRAULIC SUB-ASSEMBLY REMOVAL/INSTALLATION

3.6.1 Hydraulic Sub-Assembly Removal

3.6.3 Hydraulic Sub-Assembly Installation

3.7 BOOM WEAR PADS

3.7.1 Wear Pad Inspection

3.7.2 Boom Wear Pad Replacement

3.7.3 Boom Wear Pad Lubrication

3.8 QUICK SWITCH ASSEMBLY

3.8.1 Quick Switch Removal

3.8.2 Quick Switch Installation

3.9 FORKS

3.10 TROUBLESHOOTING

4.1 OPERATOR’S CAB AND COVERS COMPONENT TERMINOLOGY

4.2 OPERATOR’S CAB

4.2.1 Cab Safety

4.2.2 Serial Number Decal

4.3 CAB COMPONENTS

4.3.1 Steering Column and Orbitrol Valve

4.3.2 Service Brake Pedal

4.3.3 Throttle Pedal

4.3.4 Boom Joystick Assembly

4.3.5 Frame Level, Auxiliary Hydraulic and Outrigger Joysticks

4.3.6 Windshield Wiper Assembly

4.3.7 Heater/Defroster System (If equipped)

4.4 CAB REMOVAL

4.5 CAB INSTALLATION

5.1 AXLE, DRIVE SHAFT AND WHEEL COMPONENT TERMINOLOGY

5.2 GENERAL INFORMATION