JLG 120HX Service Manual

Service and Maintenance Manual

Model

120HX

P/N - 3120686

April 6, 2009

INTRODUCTION

SECTION A. INTRODUCTION - MAINTENANCE SAFETY

PRECAUTIONS

A GENERAL

This section contains the general safety precautions which must be observed during maintenance of the aerial platform. It is of utmost importance that maintenance personnel pay strict attention to these warnings and precautions to avoid possible injury to themselves or others, or damage to the equipment. A maintenance program must be followed to ensure that the machine is safe to operate.

MODIFICATION OF THE MACHINE WITHOUT CERTIFICATION BY A RESPONSIBLE AUTHORITY THAT THE MACHINE IS AT LEAST AS SAFE AS ORIGINALLY MANUFACTURED, IS A SAFETY VIOLATION.

The specific precautions to be observed during maintenance are inserted at the appropriate point in the manual. These precautions are, for the most part, those that apply when servicing hydraulic and larger machine component parts.

Your safety, and that of others, is the first consideration when engaging in the maintenance of equipment. Always be conscious of weight. Never attempt to move heavy parts without the aid of a mechanical device. Do not allow heavy objects to rest in an unstable position. When raising a portion of the equipment, ensure that adequate support is provided.

SINCE THE MACHINE MANUFACTURER HAS NO DIRECT CONTROL OVER THE FIELD INSPECTION AND MAINTENANCE, SAFETY IN THIS AREA RESPONSIBILITY OF THE OWNER/OPERATOR.

B HYDRAULIC SYSTEM SAFETY

It should be noted that the machines hydraulic systems operate at extremely high potentially dangerous pressures. Every effort should be made to relieve any system pressure prior to disconnecting or removing any portion of the system.

feed lines to system components can then be disconnected with minimal fluid loss.

C MAINTENANCE

FAILURE TO COMPLY WITH SAFETY PRECAUTIONS LISTED IN THIS SECTION MAY RESULT IN MACHINE DAMAGE, PERSONNEL INJURY OR DEATH AND IS A SAFETY VIOLATION.

• NO SMOKING IS MANDATORY. NEVER REFUEL DURING ELECTRICAL STORMS. ENSURE THAT FUEL CAP IS CLOSED AND SECURE AT ALL OTHER TIMES.

• REMOVE ALL RINGS, WATCHES AND JEWELRY WHEN PERFORMING ANY MAINTENANCE.

• DO NOT WEAR LONG HAIR UNRESTRAINED, OR LOOSE-FITTING CLOTHING AND NECKTIES WHICH ARE APT TO BECOME CAUGHT ON OR ENTANGLED IN EQUIPMENT.

• OBSERVE AND OBEY ALL WARNINGS AND CAUTIONS ON MACHINE AND IN SERVICEMANUAL.

• KEEP OIL, GREASE, WATER, ETC. WIPED FROM STANDING SURFACES AND HAND HOLDS.

• USE CAUTION WHEN CHECKING A HOT, PRESSURIZED COOLANT SYSTEM.

• NEVER WORK UNDER AN ELEVATED BOOM UNTIL BOOM HAS BEEN SAFELY RESTRAINED FROM ANY MOVEMENT BY BLOCKING OR OVERHEAD SLING, OR BOOM SAFETY PROP HAS BEEN ENGAGED.

• BEFORE MAKING ADJUSTMENTS, LUBRICATING OR PERFORMING ANY OTHER MAINTENANCE, SHUT OFF ALL POWER CONTROLS.

• BATTERY SHOULD ALWAYS BE DISCONNECTEDDURING REPLACEMENT OF ELECTRICAL COMPONENTS.

• KEEP ALL SUPPORT EQUIPMENT AND ATTACHMENTS STOWED IN THEIR PROPER PLACE.

• USE ONLY APPROVED, NONFLAMMABLE CLEANING SOLVENTS.

Relieve system pressure by cycling the applicable control several times with the engine stopped and ignition on, to direct any line pressure back into the reservoir. Pressure

3120686 – JLG Lift – A-1

INTRODUCTION

REVISON LOG

July 1, 1992 - Original Issue June 1, 1995 - Revised January, 1999 - Revised August 9, 2001 - Revised May 15, 2002 - Revised April 6, 2009 - Revised

A-2 – JLG Lift – 3120686

TABLE OF CONTENTS

SUBJECT - SECTION, PARAGRAPH PAGE NO.

SECTION A - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

A General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

B Hydraulic System Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

C Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

SECTION 1 - SPECIFICATIONS

1.1 Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Hydraulic Oil Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Hydraulic System (Including Tank) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Engine Crankcase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Diesel Engine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Drive/Steer System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Swing System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Function Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Drive Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Auxiliary Power Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Hydraulic Filter - Inline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.3 Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

Travel Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Gradeability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Turning Radius (4 Wheel Steer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Platform Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Boom Elevation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Machine Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Maximum Tire Load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Machine Height (Stowed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Machine Length (Stowed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Machine Width. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Wheelbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.4 Function Speeds (Machines Built Prior to S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

Telescope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Extend-A-Reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Swing Speed 360° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Platform Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Ground to 120’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

From 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Ground to 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.5 Function Speeds (Machines Built After S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

Telescope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Extend-A-Reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Swing Speed 360° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Platform Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Ground to 120’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

From 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Ground to 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.6 Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.7 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

Engine (Crankcase) Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

3120686 – JLG Lift – i

TABLE OF CONTENTS (Continued)

TABLE OF CONTENTS (continued)

SUBJECT - SECTION, PARAGRAPH PAGE NO.

Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.8 Pressure Settings - PSI (Bar) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8

Main Control Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Frame Mounted Control Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1.9 Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

1.10 Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9

1.11 Boom Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9

Standard Boom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

w/Boom Wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

1.12 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9

1.13 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

SECTION 2 - PROCEDURES

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.2 Servicing and Maintenance Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Safety and Workmanship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Cleanliness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Components Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Component Disassembly and Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Pressure-Fit Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Bolt Usage and Torque Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Hydraulic Lines and Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Hydraulic System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Lubrication and Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.3 Lubrication Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

Hydraulic System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Changing Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2.4 Cylinders - Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.5 Valves - Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Solenoid Control Valves (Bang-Bang) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Manual Hydraulic Control Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Crossover Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.6 Boom Chains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

Adjusting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Inspection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.7 Wear Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.8 Drift Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

Telescope Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Lift Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2.9 Cylinder Checking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

Cylinder w/o Counterbalance Valves - Steer Cylinders, Master Level Cylinder,

Frame Jack Cylinders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Cylinders w/Single Counterbalance Valves - Lift Cylinder, Telescope Cylinder,

Extend-A-Reach Cylinder. 2-10

Cylinders w/Dual Counterbalance Valve - Axle Extension Cylinders,

Telescope Cylinder, Platform Slave Level Cylinder 2-10

ii – JLG Lift – 3120686

TABLE OF CONTENTS

TABLE OF CONTENTS (continued)

SUBJECT - SECTION, PARAGRAPH PAGE NO.

2.10 Cylinder Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

Telescope Cylinder Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Telescope Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Lift Cylinder Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Lift Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Master Level Cylinder Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Master Level Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.11 Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

2.12 Boom Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

2.13 Tilt Alarm Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

Manual Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

Voltmeter Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.14 Limit Switch Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25

Boom Limit Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

Horizontal Cut-Out Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.15 Throttle Checks and Adjustments - Deutz Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25

2.16 Pressure Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25

Main Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

Frame Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

2.17 Swing Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32

Turntable Bearing Mounting Bolt Condition Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32

Wear Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

Swing Bearing Torque Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

2.18 Drive Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35

Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38

2.19 Swing Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40

Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40

Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40

2.20 swing brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-43

Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43

2.21 Drive Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-45

Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45

2.22 Free Wheeling Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-47

To Disengage Drive Motors and Brakes (Free Wheel) for Towing, etc. . . . . . . . . . . . . . . . . 2-47

To Engage Drive Motors and Brakes (Normal Operation) . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47

2.23 PQ Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48

TRIM Adjustment (Prior to S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48

TRIM Adjustment (S/N 38697 to Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-49

RAMP Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-51

3120686 – JLG Lift – iii

TABLE OF CONTENTS (Continued)

TABLE OF CONTENTS (continued)

SUBJECT - SECTION, PARAGRAPH PAGE NO.

2.24 Boom Marking Tape Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-52

2.25 Boom Length/Angle Sensor Adjusting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-52

Length Indicator Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52

Boom Angle Sensor Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52

Radius Adjust and Display Lights Setting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52

Operational Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53

Lift Down Speed Limit Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53

2.26 Load Management System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-53

Platform Position Indication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53

Overmoment Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-54

Overmoment Control Monitoring System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55

Load Management System Daily Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55

2.27 Load Management System Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58

2.28 Turntable Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58

Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58

2.29 Drive Motor Adjustment Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58

2.30 Preventive Maintenance and Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-59

SECTION 3 - TROUBLESHOOTING

3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.2 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.3 Hydraulic Circuit Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

LIST OF FIGURES

FIGURE NO. TITLE PAGE NO.

1-1. Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1-2. Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1-3. Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

2-1. Boom Chain Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

2-2. Typical Boom Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2-3. Cylinder Barrel Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2-4. Cylinder Rod Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2-5. Poly-Pak Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

2-6. Boom Assembly - Sheet 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18

2-7. Boom Assembly - Sheet 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-19

2-8. Tilt Switch Adjustment - Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24

2-9. Tilt Switch Adjustment - Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24

2-10. Throttle Checks and Adjustments - Deutz Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2-11. Pressure Setting Adjustments - Main Valve - Machines Built Before S/N 38697 . . . . . . . . . . . . . .2-28

2-12. Pressure Setting Adjustments - Frame Valve - Machines Built Before S/N 38697. . . . . . . . . . . . .2-29

2-13. Pressure Setting Adjustments - Main Valve - Machines Built After S/N 38697 . . . . . . . . . . . . . . .2-30

2-14. Pressure Setting Adjustments - Frame Valve - Machines Built After S/N 38697 . . . . . . . . . . . . . .2-31

2-15. Swing Bearing Bolt Feeler Gauge Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32

2-16. Swing Bearing Tolerance Boom Placement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-33

2-17. Swing Bearing Tolerance Measuring Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-34

2-18. Swing Bearing Bolt Torquing Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35

2-19. Drive Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36

2-20. Swing Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41

2-21. Swing Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-44

2-22. Drive Brake, Mico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-46

2-23. Spring Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47

iv – JLG Lift – 3120686

TABLE OF CONTENTS

LIST OF FIGURES (continued)

FIGURE NO. TITLE PAGE NO.

2-24. Boom Marking Tape Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-52

2-25. Control Box Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-54

2-27. Boom Length/Angle Sensor Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-56

2-28. Load Radius Circuit Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-56

2-26. Load Moment Limiting System Monitoring Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-57

2-29. Drive Motor Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-59

3-1. Electrical Diagram - Boom Length Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22

3-2. Electrical Schematic - Sheet 1 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24

3-3. Electrical Schematic - Sheet 2 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25

3-4. Electrical Schematic - Sheet 3 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-26

3-5. Electrical Schematic - Sheet 4 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27

3-6. Hydraulic Schematic - (Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-28

3-7. Hydraulic Schematic - (Sheet 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-29

LIST OF TABLES

TABLE NO. TITLE PAGE NO.

1-1 Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-2 Single Viscosity Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1-3 Multi Viscosity Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1-4 Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1-5 Lubrication Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1-6 Lubrication Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

1-7 Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9

1-8 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9

1-9 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

2-1 Chain Stretch Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2-2 Cylinder Piston Nut Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-3 Holding Valve Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-4 Function Speeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48

2-5 Platform Controller Settings (Prior to S/N 38697). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48

2-6 Platform Controller Settings (S/N 38697 to Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48

2-7 Preventive Maintenance and Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-60

3-1 Platform Assembly - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

3-2 Boom Assembly - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

3-3 Turntable Assembly - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

3-4 Chassis Assembly - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11

3-5 Hydraulic System - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17

3-6 Electrical System - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-20

3120686 – JLG Lift – v

TABLE OF CONTENTS (Continued)

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vi – JLG Lift – 3120686

SECTION 1 - SPECIFICATIONS

SECTION 1. SPECIFICATIONS

1.1 CAPACITIES

Fuel Tank

26 gallons (98 liters).

Hydraulic Oil Tank

50 gallons (189 liters).

Hydraulic System (Including Tank)

Approximately 60 gallons (227 liters).

Tor q u e H u b

Drive - 2.9 quarts (2.7 liters).

Swing - 1.4 quarts (1.3 liters).

NOTE: Torque hubs should be one half full of lubricant.

Engine Crankcase

10.0 quarts (9.5 liters) w/o filter.

1.2 COMPONENT DATA

Swing System

Swing Motor Displacement - 2.0 in.[3]/rev. (32.8 cm[3]/ rev).

Swing Brake - Automatic spring applied, hydraulically released. Release pressure 150 psi (10.5 kg/cm[2]) initial, 170 psi (12.0 kg/cm[2]) full.

Function Hydraulic Pump

Vendor - John Barnes.

Single section gear pump - 97 in.[3] (1589 cm[3]) displacement.

Output - 7.5 gpm (28.4 lpm) @ 1800 rpm; 10.5 gpm (39.7 lpm) @ 2500 rpm.

Drive Hydraulic Pump

Vendor - Sunstrand.

Overcenter piston pump - 2.8 in.[3] (45.9 cm[3]) displacement.

Output - 30 gpm (113.5 lpm) @ 2500 rpm.

Auxiliary Power Pump

Vendor - John Barnes.

Diesel Engine

Manufacturer/Model - Deutz F4L912.

Oil Capacity - 10.0 quarts (9.5 liters) w/o filter.

Low RPM - 1800.

High RPM - 2500.

Alternator - 60 Amp, belt drive.

Battery - 85 Amphour, 550 Cold Cranking Amps, 12 VDC.

Horsepower - 76 @ 2500 RPM, no load.

Drive/Steer System

Tires - 445/65R22.5, foam filled.

Drive Hub - 93.7:1 ratio.

Drive Brake - Spring applied, hydraulically released, release pressure 140 psi (9.7 bar).

Drive Motor - 2 speed, 0.4 in.[3]/rev. (6.4 cm[3]/rev.) low speed, 0.2 in.[3]/rev. (2.5 cm[3]/rev.) high speed.

Single section gear pump.

Displacement - 0.2 in.[3] (2.1 cm[3])/rev.

Output - 4.8 gpm (18 lpm).

Hydraulic Filter - Inline

Return - Bypass Type.

25 Microns Nominal.

1.3 PERFORMANCE DATA

Travel Speed

2WD - 3.2 mph (5.1 km/hr).

4WD - 2.7 mph (4.3 km/hr).

Gradeability

2WD - 25%.

4WD - 40%.

3120686 – JLG Lift – 1-1

SECTION 1 - SPECIFICATIONS

Turning Radius (4 Wheel Steer)

Outside.

19 ft. 3 in. (5.86 m) w/axles extended.

18 ft. 0 in. (5.48 m) w/axles retracted.

Inside.

8 ft. 6 in. (2.59 m) w/axles extended.

9 ft. 2 in. (2.79 m) w/axles retracted.

Platform Capacity

Standard - 500 lb. (230 kg).

Boom Elevation

Main boom - -14° to +75°.

Extend-A-Reach - +15° to -80°.

Machine Weight

Approximately 44,000 lb. (19,958 kg).

1.4 FUNCTION SPEEDS (MACHINES BUILT PRIOR TO S/N 38697)

Te le sc op e

Extend - 132-170 seconds.

Retract - 140-175 seconds.

Lift

Up - 125-160 seconds.

Down - 108-132 seconds.

Extend-A-Reach

Up - 15-25 seconds.

Down - 15-25 seconds.

Swing Speed 360°

143-243 seconds.

Maximum Tire Load

26,090 lb. (11,834 kg) @ 149 psi (10 bar).

Machine Height (Stowed)

10 ft. 3-27/32 in. (3.1 m).

Machine Length (Stowed)

Boom erected for use - 52 ft. 4 in. (15.9 m).

Boom stowed for shipping - 35 ft. 10-5/8 in. (10.9 m).

Machine Width

8 ft. 6 in. (2.6 m) w/axles retracted.

10 ft. 10 in. (3.3 m) w/ axles extended.

Wheelbase

11 ft. 4-1/2 in. (3.5 m).

Platform Rotation

Left - 20-30 seconds.

Right - 20-30 seconds.

Ground to 120’

257-330 seconds.

From 120’ to Ground

248 to 307 seconds.

Ground to 120’ to Ground

505 to 637 seconds.

1-2 – JLG Lift – 3120686

SECTION 1 - SPECIFICATIONS

1.5 FUNCTION SPEEDS (MACHINES BUILT AFTER S/N 38697)

Te le sc op e

Extend - 80-100 seconds.

Retract - 85-100 seconds.

Lift

Up - 85-100 seconds.

Down - 75-100 seconds.

Extend-A-Reach

Up - 15-25 seconds.

Down - 15-25 seconds.

Swing Speed 360°

143-243 seconds.

Platform Rotation

Left - 7-20 seconds.

Right - 7-20 seconds.

Ground to 120’

165 to 200 seconds.

From 120’ to Ground

150 to 200 Seconds

1.6 TORQUE REQUIREMENTS

Ta b l e 1 - 1 . To r q u e R e q u i r e m e n t s

Description

Bearing To Chassis 220 FT LB

Bearing To Turntable

Wheel Lugs

Drive Torque Hub to Spindle

Boom Chains

Swing Motor to Swing Brake

Swing Brake to To r qu e H u b

Torque Hub to Mounting Plate

Frame Valve Bolts

* Retorque swing bearing bolts after first 200 hours of operation and every 500 hours thereafter.

Torque Va lue

(Dry)

(298 NM)

220 FT LB

(298 NM)

300 FT LB

(407 NM)

260 FT LB

(353 NM)

59 FT LB (80

NM)

75 FT LB (102

NM)

110 FT LB

(149 NM)

260 FT LB

(353 NM)

80 IN LB (9

NM)

Interval Hours

200/500*

500

200

500

See Note

Below**

Ground to 120’ to Ground

315 to 400 Seconds

**Re-torque frame valve bolts after checking or adjusting steer pressure.

NOTE: See Section 2 for tightening sequence of turntable

bearing bolts.

NOTE: When maintenance becomes necessary or a fas-

tener has loosened, refer to the Torque Chart Figure 1-1 to determine proper torque value.

3120686 – JLG Lift – 1-3

SECTION 1 - SPECIFICATIONS

Figure 1-1. Torque Chart

1-4 – JLG Lift – 3120686

SECTION 1 - SPECIFICATIONS

1.7 LUBRICATION

Engine (Crankcase) Oil

NOTE: Crankcase oil must be a high quality detergent type

meeting one of the following API service classifications: CC/SE, CC/SF, CD/SE, CD/SF, CE/SF or CE/ SG.l

Ta b l e 1 - 2 . S i n g l e V i s c o s i t y O i l

When Outside Temperature is

Consistently

-20° F to +25° F (-29° C to -4° C) *10W

+15° F to +50° F (-10° C to +10° C) 20W-20

+40° F to ++85° F (+4° C to +30° C) 30

Above +75° F (Above +24° C) 40

Table 1-3. Multi Viscosity Oil

When Outside Temperature is

Consistently

-40° F to +75° F (-40° C to +24° C) *5W-20

-5° F to +70° F (-21° C to +21° C) 10W-30

-5° F to +85° F (-21° C to +30° C) 10W-40

+15° F to +75° F (-10° C to +24° C) 15W-30

Above +15° F (-10° C and above) 15W-40

Use SAE Viscosity

Number

Use SAE Viscosity

Number

(synthetic)

chemical stability for mobile hydraulic system service. JLG Industries recommends Kendall Hyken 052 hydraulic oil, which has an SAE viscosity of 10W-20 and a viscosity index of 152, or Mobilfluid 424, which has an SAE viscosity of 10W-30 and a viscosity index of 152. Kendall Hyken 052 and Mobilfluid 424 are fully compatible and can be mixed as necessary.

NOTE: Aside from JLG recommendations, it is not advisable

to mix oils of different brands or types, as they may not contain the same required additives or be of comparable viscosities. If use of hydraulic oil other than Kendall Hyken 052 or Mobilfluid 424 is desired, contact JLG Industries for proper recommendations. Kendall Hyken 052 and Mobilfluid 424 are fully compatible and can be mixed as necessary.

NOTE: When temperatures remain consistentlybelow 20

degrees F. (-7 degrees C), JLG Industries recommends the use of Mobil DTE11.

Lubrication Specifications

Table 1-5. Lubrication Specifications

KEY SPECIFICATIONS

MPG

EPGL Extreme Pressure Gear Lube (oil) meeting API

HO Hyd raulic Oil. API service classification GL-3, e.g.

Multipurpose Grease having a minimum dripping point of 350° F. Excellent water resistance and adhesive qualities, and being of extreme pressure type. (Timken OK 40 pounds minimum.)

service classification GL-5 or MIL-Spec MI L-L-

2105.

Kendall Hyken 052 or Mobilfluid 424.

* This viscosity can be used at colder temperatures only

with engine oil preheating.

EO Engine (crankcase) Oil. Gas - API SG/SH class,

MIL-L-2104. Diesel - API CC/CD/CE class, MIL-L2104B/MIL-L-2104C.

Hydraulic Oil

NOTE: Refer to Figure 1-2 for specific lubrication proce-

Ta b l e 1 - 4 . H y d r a u l i c O i l

HYDRAULIC SYSTEM OPERATING

TEMPERATURE RANGE

0° F to +23° F (-18° C to -5° C)

0° F to +210° F (-18° C to +99° C) 10W-20, 10W30

+50° F to +210° F (+10° C to +99° C) 20W-20

NOTE: Hydraulic oils must have anti-wear qualities at least

to API Service Classification GL-3, and sufficient

SAE VISCOSITY

GRADE

10W

3120686 – JLG Lift – 1-5

dures.

SECTION 1 - SPECIFICATIONS

Figure 1-2. Lubrication Diagram

1-6 – JLG Lift – 3120686

Table 1-6. Lubrication Chart

SECTION 1 - SPECIFICATIONS

Index

No.

Component

Wheel Drive Hubs

Steer Cylinders - Rod End

Steer Cylinders - Barrel End

King Pins

Tie Rods

Rotary Platform Stand Rotary Worm Gear

Platform Level cylinder

Platform Pivot Pin

Link Level P in

E-A-R Pivot Pin

E-A-R Lift Cylinder - Rod End

E-A-R Lift Cylinder - Barrel End

Sheave Pin - Fly Extend

Number/Type

Lube Points

Lube & Method

Interval

Hours

Fill/Drain Plugs EPGL (SAE 90) 150/

1200

2 Grease Fitting MPG - Pressure Gun 150

2 Grease Fittings MPG - Pressu re Gun 150

4 Grease Fittings MPG - Pressu re Gun 150

4 Grease Fitting MPG - Pressure Gun 150

2 Grease Fittings N/A

MPG - Pressure Gun MPG - Brush

150 150

3 Grease Fittings MPG - Pressu re Gun 150

1 Grease Fitting MPG - Pressure Gun 150

2 Grease Fittings MPG - Pressu re Gun 150

1 Grease Fitting MPG - Pressure Gun 150

Comments

Check Every 150 Hours/Change Every 1200 Hours

Remove Cover to Grea se

Sheave Pin - Upper Aux.

Tele Cyl. She ave Pin

Boom Chains

Sheave Pin - Fly Retract

Sheave P in - Outer-Mid Retra ct

Lift Cylinder - Barrel End

Master Cylinder - Barrel End

Swing Bearing

Swing Bearing Gear

Master Cylinder - Rod End

Boom Pivot Bearings

Lift Cylin der - Rod End

1 Grease Fitting MPG - Pressure Gun 150

1 Grease Fitting MPG - Pressure Gun 150 Extend boom until grease fitting is acces-

sible thru hole in f ly sec.

N/A Chain Lube/Hot Oil

1200 Extend and Re tract Chains

Dip

2 Grease Fittings MPG - Pressu re Gun 150 Extend boom until fitt ing is accessible

thru hole in fl y

2 Grease Fittings MPG - Pressu re Gun 150 Extend boom until fitt ing is accessible

thru hole in fl y

1 Grease Fitting MPG - Pressure Gun 150 Remote Access

1 Grease Fitting MPG - Pressure Gun 150 Rem ote Access. Lube, rotate 180°, lub e

again.

N/A MPG - Brush 150

1 Grease Fitting MPG - Pressure Gun 150

2 Grease Fittings MPG - Pressu re Gun 150

1 Grease Fitting MPG - Pressure Gun 150

3120686 – JLG Lift – 1-7

SECTION 1 - SPECIFICATIONS

Table 1-6. Lubrication Chart

Index

No.

Component

Load Moment Pivot Pins

Hydraulic Filter - Function Pump

Hydraulic Filter - Drive Pump

Hydraulic Fluid

Engine Crankcase

Engine Oil Filter

Platform Door Hinges

Access Door Hinges

Access Door Latches

Axle Beams

Key to Lubricants:

Number/Type

Lube Points

Lube & Method

Interval

Hours

Comments

1 Grease Fitting MPG - Pressure Gun 150 Position boom over side for access

under turntable

N/A N/A 50/300 Replace after first 50 hrs. of operation,

then every 300 hrs. the reafter

N/A N/A 50/300 Replace after first 50 hrs. of operation,

then every 300 hrs. the reafter

Fill Cap HO 10/1200 Check oil daily/Ch ange oil every 1200

hrs

Fill Cap/Drain Plug EO - SAE30 10/300 Check oil daily/Change oil every 300 hrs.

N/A Replaceable Car-

300

tridge

2 Grease Fittings MPG - Pressu re Gun 150

N/A SAE10 - Oil Can 150 As Ne eded

N/A MPG - Brush 600 As Ne eded

MPG - Multipurpose Grease EPGL - Extrem e Pressure Gear Lubricant HO - Hydraulic Fluid EO - Engine Oil

1.8 PRESSURE SETTINGS - PSI (BAR)

Frame Mounted Control Valve

Front Steer Relief - 2000 (138)

NOTE: All pressures are given in pounds per square inch

(psi), with the metric equivalent, bar, given in parentheses.

Main Control Valve

Main Relief - 3450 (238)

Lift Down Relief - 1200 (83)

Rear Steer Relief - 2000 (138)

Front Axle Extend Relief - 2000 (138)

Front Axle Retract Relief - 2200 (152)

Rear Axle Extend Relief - 2000 (138)

Rear Axle Retract Relief - 2200 (152)

Swing Relief - 1200 (83)

Level Up Relief - 2500 (172)

Level Down Relief - 2000 (138)

Rotate Relief - 2500 (172)

Extend-A-Reach Up Relief - 3000 (207)

Extend-A-Reach Down Relief - 1400 (97)

Sequence (Load Sense) - 160 (11)*

* Sequence pressure is pre-set and not normally adjusted.

1-8 – JLG Lift – 3120686

SECTION 1 - SPECIFICATIONS

1.9 SERIAL NUMBER LOCATIONS

For machine identification, a serial number plate is affixed to the machine. The plate is located on the left side of the frame, between the bearing area and the left rear wheel. If the serial number plate is damaged or missing, the machine serial number is stamped on the left side of the frame, at the center top, below the turntable bearing; the serial number is also stamped on the left side of the turntable, at center, along the left turntable upright close to the bearing area. In addition, the last five digits of the serial number are stamped on the top left of the fly end of each boom section.

1.10 MAJOR COMPONENT WEIGHTS

Table 1-7. Major Component Weights

COMPONENT LB (KG)

Platform - 36 x 72 in. (0.9 x

1.8 m) w/Control Box Support and Rotator.

Boom (Less Extend-AReach Jib and Platform)

Jib, Extend-A-Reach and Pivot Attach

Turntable Complete (Less Counterweight)

Counterweight

Lift Cylinder

Level Cylinder

243(110)

9,502 (4310)

789(358)

9,101 (4,128)

9,050 (4,105)

809 (367)

60 (27)

1.11 BOOM TAPE

Standard Boom

Red Tape - 56-1/2 in. (143.5 cm).

White Tape - 91-5/8 in. (232.7 cm)

w/Boom Wipers

Red Tape - 54-1/2 in. (138.4 cm).

White Tape - 89-5/8 in. (227.6 cm).

1.12 CYLINDER SPECIFICATIONS

NOTE: All dimensions are given in inches (in.), with the met-

ric equivalent, centimeters (cm), given in parentheses.

Table 1-8. Cylinder Specifications

DESCRIPTION BORE STROKE

Lift Cylinder 9.0

(22.9)

Master Cylinder 2.5

(6.4)

Slave Cylinder 3.5

(8.9)

Extend-A-Reach Cyl.

Telescope Cylinder 5.0

3.5

(8.9)

(12.7)

48.5

(123.2)

15.1

(38.4)

(18.5)

18.3

(46.5)

266.0

(675.6)

7.3

ROD

DIA.

4.0

(10.2)

1.3

(3.2)

1.8

(4.4)

2.5

(6.4)

3.5

(8.9)

Frame Complete (Includes Tires and Wheels)

Wheel and Tire Assembly (Each)

Complete Machine - 4WD

14,400 (6,532)

933 (423)

44,004 (19,960)

Frame Jack Cyl . (2) 5.0

(12.7)

Axle Extend Cyl. (2) 3.0

(7.6)

Steer Cylinder (2) 3.0

(7.6)

17.6

(44.8)

29.0

(73.7)

9.8

(24.9)

3.0

(7.6)

2.0

(5.1)

1.5

(3.8)

3120686 – JLG Lift – 1-9

SECTION 1 - SPECIFICATIONS

Figure 1-3. Serial Number Locations

1.13 CRITICAL STABILITY WEIGHTS

Table 1-9. Critical Stability Weights

COMPONENT WEIGHT

Counterweight

Foam-Filled Tires (each) 932 lb. (423 kg)

Deutz Engine 837 lb. (380 kg)

Platform 243 lb. (110 kg)

DO NOT REPLACE ITEMS CRITICAL TO STABILITY, SUCH AS THE COUNTERWEIGHT OR FOAM-FILLED TIRES, WITH ITEMS OF DIFFERENT WEIGHT OR SPECIFICATION. DO NOT MODIFY UNIT IN ANY WAY TO AFFECT STABILITY.

9, 050 lb. (4,105 kg)

1-10 – JLG Lift – 3120686

SECTION 2. PROCEDURES

SECTION 2 - PROCEDURES

2.1 GENERAL

This section provides information necessary to perform maintenance on the aerial platform. Descriptions, techniques and specific procedures are designed to provide the safest and most efficient maintenance for use by personnel responsible for ensuring the correct installation and operation of machine components and systems.

WHEN AN ABNORMAL CONDITION IS NOTED AND PROCEDURES CONTAINED HEREIN DO NOT SPECIFICALLY RELATE TO THE NOTED IRREGULARITY, WORK SHOULD BE STOPPED AND TECHNICALLY QUALIFIED GUIDANCE OBTAINED BEFORE WORK IS RESUMED.

The maintenance procedures included consist of servicing and component removal and installation, disassembly and assembly, inspection, lubrication and cleaning. Information on any special tools or test equipment is also provided where applicable.

2.2 SERVICING AND MAINTENANCE GUIDELINES

General

The following information is provided to assist you in the use and application of servicing and maintenance procedures contained in this chapter.

Safety and Workmanship

Cleanliness

1. The most important single item in preserving the long service life of a machine is to keep dirt and foreign materials out of the vital components. Precautions have been taken to safeguard against this. Shields, covers, seals, and filters are provided to keep air, fuel, and oil supplies clean; however, these items must be maintained on a scheduled basis in order to function properly.

2. At any time when air, fuel, or oil lines are disconnected, clear adjacent areas as well as the openings and fittings themselves. As soon as a line or component is disconnected, cap or cover all openings to prevent entry of foreign matter.

3. Clean and inspect all parts during servicing or maintenance, and assure that all passages and openings are unobstructed. Cover all parts to keep them clean. Be sure all parts are clean before they are installed. New parts should remain in their containers until they are ready to be used.

Components Removal and Installation

1. Use adjustable lifting devices, whenever possible, if mechanical assistance is required. All slings (chains, cables, etc.) should be parallel to each other and as near perpendicular as possible to top of part being lifted.

2. Should it be necessary to remove a component on an angle, keep in mind that the capacity of an eyebolt or similar bracket lessens, as the angle between the supporting structure and the component becomes less than 90 degrees.

3. If a part resists removal, check to see whether all nuts, bolts, cables, brackets, wiring, etc., have been removed and that no adjacent parts are interfering.

Component Disassembly and Reassembly

When disassembling or reassembling a component, complete the procedural steps in sequence. Do not partially disassemble or assemble one part, then start on another. Always recheck your work to assure that nothing has been overlooked. Do not make any adjustments, other than those recommended, without obtaining proper approval.

Pressure-Fit Parts

When assembling pressure-fit parts, use an “anti-seize” or molybdenum disulfide base compound to lubricate the mating surface.

Bearings

1. When a bearing is removed, cover it to keep out dirt and abrasives. Clean bearings in nonflammable cleaning solvent and allow to drip dry. Compressed air can be used but do not spin the bearing.

2. Discard bearings if the races and balls (or rollers) are pitted, scored, or burned.

3120686 – JLG Lift – 2-1

SECTION 2 - PROCEDURES

3. If bearing is found to be serviceable, apply a light coat of oil and wrap it in clean (waxed) paper. Do not unwrap reusable or new bearings until they are ready to install.

4. Lubricate new or used serviceable bearings before installation. When pressing a bearing into a retainer or bore, apply pressure to the outer race. If the bearing is to be installed on a shaft, apply pressure to the inner race.

Gaskets

Check that holes in gaskets align with openings in the mating parts. If it becomes necessary to hand-fabricate a gasket, use gasket material or stock of equivalent material and thickness. Be sure to cut holes in the right location, as blank gaskets can cause serious system damage.

Bolt Usage and Torque Application

1. Use bolts of proper length. A bolt which is too long will bottom before the head is tight against its related part. If a bolt is too short, there will not be enough thread area to engage and hold the part properly. When replacing bolts, use only those having the same specifications of the original, or one which is equivalent.

2. Unless specific torque requirements are given within the text, standard torque values should be used on heat-treated bolts, studs, and steel nuts, in accordance with recommended shop practices. (See Figure 1-1.)

Hydraulic Lines and Electrical Wiring

Clearly mark or tag hydraulic lines and electrical wiring, as well as their receptacles, when disconnecting or removing them from the unit. This will assure that they are correctly reinstalled.

Hydraulic System

1. Keep the system clean. If evidence of metal or rubber particles are found in the hydraulic system, drain and flush the entire system.

2. Disassemble and reassemble parts on clean work surface. Clean all metal parts with non-flammable cleaning solvent. Lubricate components, as required, to aid assembly.

Lubrication

Service applicable components with the amount, type, and grade of lubricant recommended in this manual, at the specified intervals. When recommended lubricants are not available, consult your local supplier for an equivalent that meets or exceeds the specifications listed.

Battery

Clean battery, using a non-metallic brush and a solution of baking soda and water. Rinse with clean water. After cleaning, thoroughly dry battery and coat terminals with an anti-corrosion compound.

Lubrication and Servicing

Components and assemblies requiring lubrication and servicing are shown in Figure 1-2.

2.3 LUBRICATION INFORMATION

Hydraulic System

1. The primary enemy of a hydraulic system is contamination. Contaminants enter the system by various means, e.g., using inadequate hydraulic oil, allowing moisture, grease, filings, sealing components, sand, etc., to enter when performing maintenance, or by permitting the pump to cavitate due to insufficient system warm-up or leaks in the pump supply (suction) lines.

2. The design and manufacturing tolerances of the component working parts are very close, therefore, even the smallest amount of dirt or foreign matter entering a system can cause wear or damage to the components and generally results in faulty operation. Every precaution must be taken to keep hydraulic oil clean, including reserve oil in storage. Hydraulic system filters should be checked, cleaned, and/or replaced as necessary, at the specified intervals required in Figure 1-2. Always examine filters for evidence of metal particles.

3. Cloudy oils indicate a high moisture content which permits organic growth, resulting in oxidation or corrosion. If this condition occurs, the system must be drained, flushed, and refilled with clean oil.

4. It is not advisable to mix oils of different brands or types, as they may not contain the same required additives or be of comparable viscosities. Good grade mineral oils, with viscosities suited to the ambient temperatures in which the machine is operating, are recommended for use.

NOTE: Metal particles may appear in the oil or filters of new

machines due to the wear-in of meshing components.

2-2 – JLG Lift – 3120686

SECTION 2 - PROCEDURES

Hydraulic Oil

1. Refer to Table 1-1 for recommendations for viscosity ranges.

2. JLG recommends Kendall Hyken 052 hydraulic oil, which has an SAE viscosity of 10W-20 and a viscosity index of 152 or Mobilfluid 424 hydraulic oil, which has an SAE viscosity of 10W-30 and a viscosity index of 152. Kendall Hyken 052 and Mobilfluid 424 are fully compatible, and can be mixed as necessary.

NOTE: Start-up of hydraulic system with oil temperatures

below -15 degrees F (-26 degrees C). is not recommended. If it is necessary to start the system in a sub-zero environment, it will be necessary to heat the oil with a low density, 100VAC heater to a minimum temperature of -15 degrees F (-26 degrees C).

3. The only exception to the above is to drain and fill the system with Mobil DTE 11 oil or its equivalent. This will allow start up at temperatures down to -20 degrees F (-29 degrees C). However, use of this oil will give poor performance at temperatures above 120 degrees F (49 degrees C). Systems using DTE 11 oil should not be operated at temperatures above 200 degrees F (94 degrees C) under any condition.

Changing Hydraulic Oil

1. Use of any of the recommended crankcase or hydraulic oils eliminates the need for changing the oil on a regular basis. However, filter elements must be changed after the first 40 hours of operation and every 250 hours thereafter. If it is necessary to change the oil, use only those oils meeting or exceeding the specifications appearing in this manual. If unable to obtain the same type of oil supplied with the machine, consult local supplier for assistance in selecting the proper equivalent. Avoid mixing petroleum and synthetic base oils. JLG Industries recommends changing the hydraulic oil annually.

2. Use every precaution to keep the hydraulic oil clean. If the oil must be poured from the original container into another, be sure to clean all possible contaminants from the service container. Always clean the mesh element of the filter and replace the cartridge any time the system oil is changed.

3. While the unit is shut down, a good preventive maintenance measure is to make a thorough inspection of all hydraulic components, lines, fittings, etc., as well as a functional check of each system, before placing the machine back in service.

Lubrication Specifications

Specified lubricants, as recommended by the component manufacturers, are always the best choice, however, multi-purpose greases usually have the qualities which meet a variety of single purpose grease requirements. Should any question arise regarding the use of greases in maintenance stock, consult your local supplier for evaluation. Refer to Table 1-2 for an explanation of the lubricant key designations appearing in the Lubrication Chart.

2.4 CYLINDERS - THEORY OF OPERATION

Cylinders are of the double acting type. Systems incorporating double acting cylinders are as follows: Lift, Telescope, Steer, Master Level, Slave Level, Frame Lift, Axle Extend and Extend-A-Reach. A double acting cylinder is one that requires oil flow to operate the cylinder rod in both directions. Directing oil (by actuating the corresponding control valve to the piston side of the cylinder) forces the piston to travel toward the rod end of the barrel, extending the cylinder rod (piston attached to rod). When the oil flow is stopped, movement of the rod will stop. By directing oil to the rod side of the cylinder, the piston will be forced in the opposite direction and the cylinder rod will retract.

Holding valves are used in the Lift, Platform Level, Telescope, and Extend-A-Reach circuits to prevent retraction of the cylinder rod should a hydraulic line rupture or a leak develop between the cylinder and its related control valve.

2.5 VALVES - THEORY OF OPERATION

Solenoid Control Valves (Bang-Bang)

Control valves used are four-way three-position solenoid valves of the sliding spool design. When a circuit is activated and the control valve solenoid energizes, the spool is shifted and the corresponding work port opens to permit oil flow to the component in the selected circuit, with the opposite work port opening to reservoir. Once the circuit is deactivated (control returned to neutral), the valve spool returns to neutral (center) and oil flow is then directed through the valve body and returns to reservoir. A typical control valve consists of the valve body, sliding spool, and two solenoid assemblies. The spool is machine fitted in the bore of the valve body. Lands on the spool divide the bore into various chambers, which, when the spool is shifted, align with corresponding ports in the valve body open to common flow. At the same time other ports would be blocked to flow. The spool is springloaded to center position, therefore when the control is released, the spool automatically returns to neutral, prohibiting any flow through the circuit.

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Manual Hydraulic Control Valves

The manual hydraulic control valves consist of four-way, multi-position valve sections, each section incorporating a sliding spool, spring-loaded to neutral or off. Each spool is attached to a control lever which provides for proportional control of the selected system function. This proportional control enables metering of oil flow in accordance with spool position, affording variable and smooth speed control capability. Spool movement causes work ports within the valve to align in a predetermined way, permitting flow to the selected function, with the opposing work ports positioned to allow return flow to the hydraulic reservoir.

Relief Valves

Main relief valves are installed at various points with the hydraulic system to protect associated systems and components against excessive pressure. Excessive pressure can be developed when a cylinder reaches its limit of travel and the flow of pressurized fluid continues from the system control. The relief valve provides an alternate path for the continuing flow from the pump, thus preventing rupture of the cylinder, hydraulic line or fitting. Complete failure of the system pump is also avoided by relieving circuit pressure. The relief valve is installed in the circuit between the pump outlet (pressure line) and the cylinder of the circuit, generally as an integral part of the system valve bank. Relief pressures are set slightly higher than the load requirement, with the valve diverting excess pump delivery back to the reservoir when operating pressure of the component is reached.

2.6 BOOM CHAINS

Adjusting Procedures

ENSURE MACHINE IS ON A FIRM AND LEVEL SURFACE.

1. Position boom fully retracted at +5 degrees horizontal, no load in platform.

2. Torque outer mid section extend chain adjuster to 59 ft. lb. (80 Nm).

3. Torque outer mid section retract chain adjuster to 59 ft. lb. (80 Nm).

4. Torque fly section extend chain adjuster to 59 ft. lb. (80 Nm).

5. Torque fly section retract chain adjuster to 59 ft. lb. (80 Nm).

6. Cycle boom (extend at least 6 feet (2 meters), then retract fully).

7. Recheck outer mid section extend chain.

8. Recheck outer mid section retract chain.

9. Recheck fly section extend chain.

10. Recheck fly section retract chain.

11. Repeat steps (2) thru (10) if necessary.

Crossover Relief Valves

Crossover relief valves are used in circuits where the actuator requires an operating pressure lower than that supplied to the system. When the circuit is activated and the required pressure at the actuator is developed, the crossover relief diverts excess pump flow to the reservoir. Individual, integral reliefs are provided for each side of the circuit.

12. Check for proper operation of boom.

JLG Industries, Inc. requires a complete boom disassembly, per the instructions outlined in paragraph 2-11, Boom Maintenance, every two years. All boom chains and related components (i.e., sheaves, pins, sprockets, wear pads, etc.) must also be inspected and replaced, as necessary, during this disassembly.

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Figure 2-1. Boom Chain Adjustments

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Figure 2-2. Typical Boom Assembly

An immediate disassembly of the boom assembly and inspection of the boom chains and related components is required if any of the following conditions occur:

1. After machine is exposed to hostile environments or conditions (i.e., extreme cold, dust, sand, blasting grit, salt, chemicals, etc.) which could adversely affect boom operation.

2. Erratic boom operation or unusual noise exists. Refer to troubleshooting tables in Section 3.

3. Chain adjustment is required more often than specified in this Section or links need to be removed (chain shortened) to make adjustment.

4. Machine is idle for an extended period (6 months or longer).

5. Boom is overloaded or has sustained a shock load.

FAILURE TO DISASSEMBLE THE BOOM ASSEMBLY AND PROPERLY INSPECT AND/OR REPLACE THE BOOM CHAINS AND RELATED COMPONENTS (I.E., SHEAVES, PINS, SPROCKETS, WEAR PADS, ETC.) COULD RESULT IN THE DAMAGE AND/OR BREAKAGE OF THE BOOM CHAINS AND/OR RELATED COMPONENTS. DAMAGE AND/OR BREAKAGE OF THESE ITEMS COULD RESULT IN UNCONTROLLED EXTENSION OR RETRACTION OF THE BOOM ASSEMBLY AND COULD CAUSE SERIOUS INJURY OR DEATH TO PERSONNEL OPERATING THE JLG BOOM LIFT.

Inspection Procedure

BOOM CHAINS TO BE INSPECTED AT TIME OF NEXT BOOM OVERHAUL AND WHEN DEEMED NECESSARY BY MACHINE OWNER, BUT NOT TO EXCEED 2 YEARS OF MACHINE OPERATION.

1. Inspect boom chains for the following conditions:

a. Wear: Always inspect that segment of chain that

operates over a sheave. As the chain flexes over the extend/retract sheaves, joints and plate edges very gradually wear. Chain “stretch” can be measured using a manufacturers wear scale or steel tape. When chains have elongated 3% they must be removed and replaced. Refer to Table 2-1 for proper chain specifications and allowable stretch tolerances. Peening and wear of chain plate edges are caused by sliding over a chain worn contact face of a sheave, or unusually heavy loads. All of the above require replacement of the chain and correction of the cause. Chain side wear, noticeable when pin heads and outside plates show a definite wear pattern, is caused by misalignment of the sheave/chain anchors and must be corrected promptly. Do not repair chains; if a section of chain is damaged, replace the entire chain set.

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b. Lubrication: One of the most important but often

overlooked factors is adequate lubrication. In addition to reducing internal friction, maintaining a film of oil on all chain surfaces will inhibit rusting and corrosion. This is important as corrosion of highly stressed, hardened steel chain components can cause a major reduction in the load capacity of leaf chain and result in link plate cracking.

NOTE: The need for lubrication can be determined by the

presence of rust on the exposed portions of chain.

c. Rust and Corrosion: Rust and corrosion will

cause a major reduction in the load carrying capacity of the chain, because these are primary reasons for side plate cracking. The initial lubrication at the factory is applied in a hot dip tank to assure full penetration into the joint. Do not steam clean or degrease this lubricant of chains. At time of chain installation, factory lube must be supplemented by a maintenance program to provide a film of oil on the chains at all times. A grade of SAE 30 or 40 weight, non-detergent motor oil should be used as a supplemental lubricant and a film of this oil should be constantly maintained on the surfaces and internal joints. If chains are corroded, they must be inspected, especially the outside plates, for cracks in-line with the pins. If cracks are found, replace the chain; if no cracks are discovered, lubricate the chains by dipping in heated oil, and reinstall on the machine. Keep chains lubricated.

d. Fatigue Cracks: Fatigue is a phenomenon that

affects most metals, and is the most common cause of chain plate failures. Fatigue cracks are found through the link holes, perpendicular (90 degrees) from the pin in-line position. Inspect chains carefully after long time use and heavy loading for this type of crack. If any cracks are discovered, replace all chains, as seemingly sound plates are on the verge of cracking. Fatigue and ultimate strength failures on JLG Lifts are incurred as a result of severe abuse as design specs are well within the rated lifting capacity of these chains.

e. Tight Joints: All joints in the roller chain should

flex freely. On roller chain, tight joints are usually caused by rust/corrosion, or the inside plates “walking” off the bushing. Limber up rusty/corroded chains (after inspecting carefully) with a heavy application of oil (preferably a hot oil dip). Tap inside “walking” plates inward; if “walking”

persists, replace the chain. This type of problem is accelerated by poor lubrication maintenance practice, and most tight joint chains have been operated with little or no lubrication. Tight joints on leaf chain are generally caused by:

1. Bent pins or plates.

2. Rusty joints.

3. Peened plate edges.

Oil rusty chains, and replace chains with bent or peened chain components. Keep chains lubricated.

TIGHT JOINTS

f. Protruding or Turned Pins: Chains operating

with inadequate lube generate tremendous friction between the pin and plates (pin and bushing on roller chain). In extreme cases, this frictional torque can actually turn the pins in the outside press-fit plates. Inspect for turned pins, which can be easily spotted as the “V” flats on the pin heads are no longer in line. Replace all chains showing evidence of turned or protruding pins. Keep chains lubricated.

ABNORMAL PROTRUSION OR

TURNED PINS

g. Stress Corrosion Cracking: The outside link

plates, which are heavily press-fitted to the pins, are particularly susceptible to stress corrosion cracking. Like fatigue cracks, these initiate at the point of highest stress (aperture) but tend to extend in an arc-like path, often parallel to the rolling grain of the material.

Also, more than one crack can often appear on a link plate. In addition to rusting, this condition can be caused by exposure to an acidic or caustic medium or atmosphere. Stress corrosion is an environmentally assisted failure. Two conditions must be present - corrosive agent and static stress. In the chain, static stress is present at the aperture due to the press fit pin. No cycle motion is required and the plates can crack during idle periods. The reactions of many chemical agents (such as battery acid fumes) with hard-

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SECTION 2 - PROCEDURES

ened metals liberate hydrogen which attacks and weakens the metal grain structure.

ARC-LIKE CRACKED PLATES

(STRESS CORROSION)

h. Chain Anchors and Sheaves: An inspection of

the chain must include a close examination of chain anchors and sheaves. Check chain anchors for wear breakage and misalignment. Anchors with worn or broken fingers should be replaced. They should also be adjusted to eliminate twisting the chain for an even load distribution.

Sheaves should be inspected for worn flanges, which would indicate misalignment, and wear on the outside diameter of the sheave. A worn sheave can mean several problems, as follows:

1. Chains too tight.

2. Sheave bearings/pin bad.

3. Bent/misaligned chains.

Table 2-1. Chain Stretch Tolerance

2.8 DRIFT TEST

NOTE: It is recommended that the machine be shut down in

the test mode for at least one hour prior to beginning the drift test. This will allow the oil temperature in the cylinder to stabilize with the ambient temperature. Thermal expansion or retraction of the hydraulic oil can greatly affect cylinder movement.

Telescope Cylinder

NOTE: Switches referenced in this procedure are located on

the Ground Control Panel.

1. Activate hydraulic system, properly set extendable axles and position boom in stowed position; adhere to all safety precautions.

BEFORE RAISING AND EXTENDING BOOM, ENSURE THAT AREAS ABOVE AND BELOW BOOM AND PLATFORM AND AHEAD OF PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PERSONNEL.

2. Position LIFT control switch to UP and hold until boom reaches horizontal.

ALLOWABLE

STRETCH 14 IN.

SPAN

0.42 in. (1.07 cm)

CHAIN SIZE

0.50 in. (1.27 cm) pitch

1.00 in. (2.54 cm) pitch

1.75 in. (4.45 cm) pitch

2.00 in. (5.08 cm) pitch

PIN TO PIN

MEASUREMENT

14 in. (36 cm) or

28 pitches

14 in. (36 cm) or

14 pitches

14 in. (36 cm) or 8

pitches

14 in. (36 cm) or 7

pitches

2.7 WEAR PADS

Shim up wear pads to within 1/16 in. (1.6 mm) tolerance between wear pad and adjacent surface.

Replace wear pads when worn within 1/8 in. (3.2 mm) of threaded insert.

3. Position TELESCOPE control switch to OUT and hold until boom extends approximately four (4) feet (1.2 meter); measure from end of base section to end of mid section.

4. Position LIFT control switch to UP and hold until boom reaches maximum elevation. Shut down engine.

5. Tag and carefully disconnect the hydraulic lines to the telescope cylinder at control valve.

6. Observe oil flow from cylinder lines. Oil leaking from extend port hose indicates a leaking counterbalance valve. Oil leaking from retract port hose indicates leakage by cylinder piston.

7. Leave boom elevated in test position for approximately one hour.

BEFORE LOWERING BOOM, ENSURE THAT AREAS BELOW BOOM AND PLATFORM ARE CLEAR OF ALL PERSONNEL AND OBSTRUCTIONS.

8. Position LIFT control switch to DOWN and hold until boom reaches horizontal; check boom length against measurement. If boom has retracted more than 1 inch (2.5 cm) and oil is leaking around rodend of telescope cylinder (check with light and inspection mirror), seals are defective and require

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replacement, or cylinder rod is scored and cylinder requires overhaul or replacement. If boom has retracted and oil is leaking from counterbalance valve, the valve is either improperly adjusted, or defective and requires replacement.

9. Connect hydraulic lines to control valve.

Lift Cylinder

NOTE: Switches referenced in this procedure are located on

the Ground Control Panel.

1. Activate hydraulic system, properly set extendable axles and position boom in stowed position; adhere to all safety precautions.

NOTE: Tape measure or cord should be at least 7 feet (2.1

meters) long for use in this test.

2. Attach tape measure or cord to bottom of platform.

BEFORE RAISING BOOM, ENSURE THAT AREAS ABOVE AND BELOW BOOM AND PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PERSONNEL.

3. With boom fully retracted, place LIFT control switch to UP and hold until platform is approximately 6 feet (2 meters) above ground level. Shut down engine.

4. Tag and carefully disconnect hydraulic lines to lift cylinder at control valve. Use a suitable container to retain any residual hydraulic fluid.

5. Observe oil flow from cylinder lines. Oil leaking from extend port hose indicates a leaking counterbalance valve. Oil leaking from retract port hose indicates leakage by cylinder piston.

6. Leave boom elevated in test position for approximately one (1) hour.

7. With tape measure or cord used for reference, check to see whether boom has lowered (crept) more than 3 inches (7.6 cm).

8. If boom has lowered and oil is leaking around rodend cap of cylinder, seals in cylinder are defective and require replacement. If boom has lowered and oil is leaking from the counterbalance valve, the valve is either improperly adjusted or defective and requires replacement.

ENSURE THAT HYDRAULIC LINES ARE CONNECTED AS MARKED PRIOR TO BEING DISCONNECTED.

9. Connect hydraulic lines to control valve.

2.9 CYLINDER CHECKING PROCEDURES

NOTE: Cylinder checks must be performed any time a cylin-

der component is replaced or when improper system operation is suspected.

Cylinder w/o Counterbalance Valves - Steer Cylinders, Master Level Cylinder, Frame Jack Cylinders.

OPERATE FUNCTIONS FROM GROUND CONTROL STATION ONLY.

1. Using all applicable safety precautions, activate engine and fully extend cylinder to be checked. Shut down engine.

2. Carefully disconnect hydraulic hose from retract port of cylinder. There will be initial weeping of hydraulic fluid which can be caught in a suitable container. After the initial discharge, there should be no further leakage from the retract port.

3. Activate engine and activate cylinder extend function. Check retract port for leakage.

4. If cylinder leakage is 6-8 drops per minute or more, piston seals are defective and must be replaced. If cylinder retract port leakage is less than 6-8 drops per minute, carefully reconnect hose to retract port and retract cylinder.

5. With cylinder fully retracted, shut down engine and carefully disconnect hydraulic hose from cylinder extend port.

6. Activate engine and activate cylinder retract function. Check extend port for leakage.

7. If cylinder leakage is 6-8 drops per minute or more, piston seals are defective and must be replaced. If extend port leakage is less than 6-8 drops per minute, carefully reconnect hose to extend port, then activate cylinder through one complete cycle and check for leaks.

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SECTION 2 - PROCEDURES

Cylinders w/Single Counterbalance Valves Lift Cylinder, Telescope Cylinder, Extend-AReach Cylinder.

OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION ONLY.

1. Using all applicable safety precautions, activate hydraulic system.

WHEN WORKING ON THE LIFT CYLINDER, RAISE THE BOOM TO HORIZONTAL AND SUPPORT THE BOOM USING A SUITABLE BOOM PROP OR OVERHEAD LIFTING DEVICE.

2. If working on the lift cylinder, raise boom to horizontal and place a suitable boom prop approximately 1 inch (2.5 cm) below the boom. If working on the telescope cylinder, raise the boom above horizontal and extend the fly boom approximately 1 foot (30.5 cm).

3. Shut down hydraulic system and allow machine to sit for 10-15 minutes. Turn ignition switch to ON, move control switch or lever for applicable cylinder in each direction, then turn ignition switch to OFF. This is done to relieve excess pressure in the hydraulic lines. Carefully remove hydraulic hoses from appropriate cylinder port block.

4. There will be initial weeping of hydraulic fluid, which can be caught in a suitable container. After the initial discharge, there should not be any further leakage from the ports. If leakage continues at a rate of 6-8 drops per minute or more, cylinder repairs must be made. If the retract port is leaking, the piston seals are defective and must be replaced. If the extend port is leaking, the counterbalance valve is defective and must be replaced.

5. If no repairs are necessary or when repairs have been made, carefully reconnect hydraulic hoses to the appropriate ports.

Cylinders w/Dual Counterbalance Valve Axle Extension Cylinders, Telescope Cylinder, Platform Slave Level Cylinder

OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION ONLY.

1. Using all applicable safety precautions, activate hydraulic system.

2. If working on the telescope cylinder, raise the boom above horizontal and extend the fly boom approximately 1 foot (30.5 cm). If working on the platform slave level cylinder, stroke platform level cylinder forward until platform sits at a 45° angle.

3. Shut down hydraulic system and allow machine to sit for 10-15 minutes. Turn ignition switch to ON, move control switch or lever for applicable cylinder in each direction, then turn ignition switch to OFF. This is done to relieve pressure in the hydraulic lines. Carefully remove hydraulic hoses from appropriate cylinder port block.

4. There will be initial weeping of hydraulic fluid which can be caught in a suitable container. After the initial discharge, there should not be any further leakage from the ports. If leakage continues at a rate of 6-8 drops per minute or more, the counterbalance valve is defective and must be replaced.

5. To check piston seals, carefully remove the counterbalance valve from the retract port. After initial discharge, there should not be any further leakage from the ports. If leakage occurs at a rate of 6-8 drops per minute or more, the piston seals are defective and must be replaced.

6. If no repairs are necessary or when repairs have been made, replace counterbalance valve and carefully reconnect hydraulic hoses to cylinder port block.

7. Activate hydraulic system and run cylinder through one complete cycle to check for leaks.

6. If used, remove boom prop or lifting device from boom, activate hydraulic system and run cylinder through one complete cycle to check for leaks.

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