JLG 450AJ Service Manual

Service and Maintenance Manual

Model

450A

450AJ

3120869

February 16, 2000

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 VIOLA-

TION.

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/OPER-

ATOR.

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.

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.

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

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

•USE ONLY APPROVED, NONFLAMMABLE CLEANING SOLVENTS.

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A-1

INTRODUCTION

	REVISON LOG
May, 1998	- Original Issue
August 5, 1999	- Revised
2-54 thru 2-57	- Updated 10-12-99
2-59	- Updated 10-12-99
1-4 thru 1-6	- Updated 11-1-99
2-26	- Updated 11-1-99
1-2 and 1-3	- Updated 2-16-00
2-59 thru 2-62	- Updated 2-16-00

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TABLE OF CONTENTS

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
1.2	Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-1
1.3	Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-1
1.4	Specifications and Performance Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-1
1.5	Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-2
1.6	Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-2
1.7	Pressure Settings - PSI (Bar). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-3
1.8	Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-3
1.9	Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-3
1.10	Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-3
1.11	Function Speeds (in Seconds) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-7
1.12	Serial Number Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1-7

SECTION 2 - PROCEDURES

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1 2.2 Service and Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1 2.3 Lubrication and Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2 2.4 Cylinders - Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3 2.5 Valves - Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4 2.6 Boom Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4 2.7 Drift Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7 2.8 Cylinder Checking Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8 2.9 Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9 2.10 Mid and Lower Lift Cylinder Bleeding Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16 2.11 Hydraulic Pump (gear) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16 2.12 Swing Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23 2.13 Worm gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27 2.14 Boom Synchronizing Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27 2.15 Extend-A-Reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28 2.16 Adjustment Procedure For Lockout Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28 2.17 Torque Hub (Prior to S/N 39594) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-29 2.18 Torque Hub (S/N 39594 to Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-34 2.19 Drive Brake (Ausco) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-45 2.20 Boom Limit Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48 2.21 Lift Up and Platform Level Down Disable Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48 2.22 Throttle Checks and Adjustments - Deutz Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-49 2.23 Drive and Steer Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-51 2.24 Lift and Swing Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-53 2.25 Function Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-53 2.26 Tilt Alarm Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-55 2.27 Pressure Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-55 2.28 Hydraulic Component Start-Up Procedures and Recommendations . . . . . . . . . . . . . . . . . . . . . .2-59 2.29 Semi-Track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-61 2.30 Preventive Maintenance and Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-63

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TABLE OF CONTENTS

TABLE OF CONTENTS (continued)

SUBJECT - SECTION, PARAGRAPH

PAGE NO.

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. Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4 1-2. Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7 1-3. Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8 2-1. Location of Components - Boom Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4 2-2. Location of Components - Removal of Telescope Cylinder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5 2-3. Location of Components - Front Wear Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6 2-4. Boom Prop Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10 2-5. Cylinder Barrel Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11 2-6. Capscrew Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11 2-7. Cylinder Rod Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11 2-8. Tapered Bushing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12 2-9. Gar-Max Bearing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12 2-10. Rod Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13 2-11. Wiper Seal Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13 2-12. Installation of Head Seal Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13 2-13. Piston Seal Kit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14 2-14. Tapered Bushing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14 2-15. Seating the Tapered Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15 2-16. Poly-Pak Piston Seal Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15 2-17. Rod Assembly Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15 2-19. Swing Bearing Feeler Gauge Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23 2-18. Swing Bearing Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24 2-20. Swing Bearing Tolerance Measuring Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25 2-21. Swing Bearing Torquing Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-26 2-22. Synchronizing Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27 2-23. Extend-A-Reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28 2-24. Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-29 2-25. Ring Gear/Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-29 2-26. Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-30 2-27. Torque Hub (Prior to S/N 39594) - Exploded View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-31 2-28. Torque Hub (Prior to S/N 39594) - Cutaway View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32 2-29. Torque Hub (S/N 39594 to Present) - Cutaway View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35 2-30. Cluster Gear Punch Marks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-43 2-31. Drive Brake (Ausco) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-46 2-32. Switch Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48 2-33. Functional Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48 2-34. Addco Adjustments - Deutz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-49 2-35. Drive and Steer Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-52 2-36. Lift and Swing Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-53 2-37. Function Control Card Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-54 2-38. Tilt Switch Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-55 2-39. Main Valve (Proportional Controls) - Sheet 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-56 2-40. Main Valve (Proportional Controls) - Sheet 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-57 2-41. Valve Location - Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58

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LIST OF FIGURES (continued)

FIGURE NO. TITLE

PAGE NO.

3-1. Electrical Components Installation - Sheet 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-20 3-2. Electrical Components Installation - Sheet 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21 3-3. Electrical Schematic - Boom, Turntable, Chassis - Deutz - Sheet 1 . . . . . . . . . . . . . . . . . . . . . . .3-22 3-4. Electrical Schematic - Boom, Turntable, Chassis - Deutz - Sheet 2 . . . . . . . . . . . . . . . . . . . . . . .3-23 3-5. Electrical Schematic - Platform -Deutz - Sheet 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24 3-6. Electrical Schematic - Platform -Deutz - Sheet 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25 3-7. Hydraulic Schematic - Proportional Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-26

LIST OF TABLES

TABLE NO. TITLE

PAGE NO.

1-1 Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-2 Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-3 Lubrication Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-4 Mobil EAL Envirosyn H 46 Specs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-5 Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-6 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-7 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-8 Lubrication Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

2-1 Cylinder Head and Tapered Bushing Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-2 Holding Valve Torque Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-3 Hydraulic Pump Bolt Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22

2-4 Position Controller Truth Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-49

2-5 Adjustment Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-62

2-6 Preventive Maintenance and Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-64

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

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

3-3 Turntable Assembly - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8

3-4 Chassis Assembly - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9

3-5 Hydraulic System - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15

3-6 Electrical System - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-18

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TABLE OF CONTENTS

This Page Left Blank Intentionally.

iv

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3120869

SECTION 1 - SPECIFICATIONS

SECTION 1. SPECIFICATIONS

1.1CAPACITIES

Fuel Tank - 62.5 liters

Hydraulic Oil Tank - 106 liters

Torque Hub - 0.5 liters

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

Engine Crankcase (Ford LRG425) - 4.5 L

Engine Crankcase (Deutz F3M1011F) - 6 L

1.2COMPONENT DATA

Engine - Deutz F3M1011F

Fuel - Diesel

No. of Cylinders - 3

BHP at Max. RPM - 48

RPM Setting (No Load) - Mid - 1500

1.3TIRES

12x16.5

•Pneumatic - 6 Bar

•Weight: 58 kg 12x16.5

•Foam-Filled

•Weight: 149 kg 33/1550x16.5

•Pneumatic - 6 Bar

•Weight: 61 kg 33/1550x16.5

•Foam-Filled

•Weight: 179 kg 33/16LL x 16.1

•Pneumatic - 3 bar

•Weight: 41.5 kg 33/16LL x 16.1

•Foam-Filled

•Weight: 193 kg

1.4SPECIFICATIONS AND PERFORMANCE DATA

Max. Platform Height - 13.8 M

Max. Horizontal Reach - 7.3 M

Unrestricted Rated Capacity - 230kg

Maximum Capacity - 230 kg

Maximum Tire Load (450A) - 3230 kg

Maximum Tire Load (450AJ) - 3357 kg

Overall Width - 1.98 m

Tailswing - Zero

Stowed Height - 2.24 m

Stowed Length - 6.15 m

Wheelbase - 1.98 m

Ground Clearance - 28 cm

Platforms - 0.76m x 1.22M 0.76m x 1.52M 0.76m x 1.83M

Rated Gradeability - 2WD -30%

4WD - 40%

System Voltage - 12 Volts

Max. Hydraulic System Operating Pressure - 207 bar

Travel Speed (2WD) - 7.2 kph

Travel Speed (4WD) - 3.6 mph

Ground Bearing Pressure (450A)

12x16.5 pneu. - 3.23 kg/cm2

12x16.5 FF - 3.93 kg/cm2

33/1550x16.5 pneu. - 2.46 kg/cm2

33/1550x16.5 FF - 3.51 kg/cm2

Ground Bearing Pressure (450AJ)

12x16.5 pneu. - 3.37 kg/cm2

12x16.5 FF - 4.07 kg/cm2

33/1550x16.5 pneu. - 2.53 kg/cm2

33/1550x16.5 FF - 3.65 kg/cm2

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1-1

SECTION 1 - SPECIFICATIONS

1.5TORQUE REQUIREMENTS

Table 1-1.Torque Requirements

Description	Torque Value	Interval Hours
Wheel Lugs	170 ft. lbs.	150
	(231 Nm)
Semi-Track	90 ft. lbs.	150
Wheel Lugs	(122 Nm)
Swing Bearing	220 ft. lbs.	50/600*
(Dry)	(298 Nm)
Swing Bearing	240 ft. lbs.	50/600*
((Loctite)	(326 Nm)

* Check swing bearing bolts for security after first 50 hours of operation and every 600 hours thereafter.

1.6 LUBRICATION

Hydraulic Oil

Table 1-2.Hydraulic Oil

	Hydraulic System	S.A.E. Viscosity
	Operating
		Grade
	Temperature Range
	+0° to + 180° F	10W
	(-18° to +83° C)
	+0° to + 210° F	10W-20, 10W30
	(-18° to +99° C)
	+50° to + 210° F	20W-20
	(+10° to +99° C

NOTE: Hydraulic oils must have anti-wear qualities at least to API Service Classification GL-3, and sufficient chemical stability for mobile hydraulic system service. JLG Industries recommends Mobilfluid 424 hydraulic oil, which has an SAE viscosity index of 152.

NOTE: When temperatures remain consistently below 20 degrees F. (-7 degrees C.), JLG Industries recommends the use of Mobil DTE11.

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 Mobilfluid 424 is desired, contact JLG Industries for proper recommendations.

Some machines may be specially equipped with Mobil EAL224H biodegradable and non-toxic hydraulic oil. This oil is vegetable oil based and possesses the same anti-

Updated 2-16-00

wear and rust protection characteristics as mineral oils, but will not adversely affect ground water or the environment when spilled or leaked in small amounts. Mobil

EAL224H has a viscosity of 34 cST at 40° C and a viscosity index of 213. The operating range of this oil is -18° C to +83° C.

IT IS RECOMMENDED THAT MOBIL EAL224H HYDRAULIC OIL BE STORED ABOVE FREEZING (0° C) AS THE OIL MAY APPEAR CLOUDY AFTER EXPOSURE TO LOW TEMPERATURES FOR EXTENDED PERIODS OF TIME. THE CLOUDINESS WILL DISAPPEAR WHEN THE OIL IS WARMED TO AT LEAST 10° C AND AGITATED. DO NOT ATTEMPT TO "THIN" THE OIL WITH NO.2 DIESEL FUEL. FOR BEST RESULTS, STORE THE OIL ABOVE FREEZING.

NOTE: Accidentally mixing Mobil EAL224H hydraulic oil with other mineral oils will cause no loss of performance characteristics. However, biodegradability may be reduced and toxicity may be increased, depending on the oil and level of contamination.

Lubrication Specifications

	Table 1-3.Lubrication Specifications.
KEY		SPECIFICATIONS
MPG		Multipurpose Grease having a minimum dripping point of 350
		degrees F. Excellent water resistance and adhesive qualities; and
		being of extreme pressure type (Timken OK 40 pounds minimum).
EPGL		Extreme Pressure Gear Lube (oil) meeting API Ser-
		vice Classification GL-5 or Mil-Spec Mil-L-2105.
HO		Hydraulic Oil. API Service Classification GL-3, SAE
		10W-20, Viscosity Index 152, e.g. Kendall Hyken 052.
EO		Engine (crankcase) Oil. Gas - API SF/SG class, MIL-L-
		2104. Diesel - API CC/CD class, MIL-L-2104B/MIL-L-
		2104C.

NOTE: Refer to Lubrication Chart for specific lubrication procedures..

Table 1-4. Mobil EAL Envirosyn H 46 Specs

Type		Synthetic Biodegradable
ISO Viscosity Grade		46
Specific Gravity		.910
Pour Point, Max		-44° F (-44° C)
Flash Point, Min.		500° F (260° C)
Weight		7.64 lb. per gal.
		(0.9 kg per liter)
	Viscosity
at 40° C		45 cSt
at 100° C		8.0 cSt
Viscosity Index		153

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3120869

SECTION 1 - SPECIFICATIONS

1.7PRESSURE SETTINGS - PSI (BAR)

Main Relief

Main Relief - 3000 (207)

Lift Up - 3000 (207) - Governed by Main Relief

Lift Down - 2500 (172) - Governed by Level Down Relief Level Down - 2500 (172)

Level Up - 2500 (172)

Swing (Right & Left) - 1750 (121)

Drive

Drive - Pre-Set 4500 (310)

1.8MAJOR COMPONENT WEIGHTS

Table 1-5.Major Component Weights

Component	LB.	KG.
6 ft Platform	160	73
5 ft. Platform	145	66
4 ft. Platform	130	59
Extend-A-Reach	230	104
Upper Boom (450A)	985	447
Upper Boom (450AJ)	1250	567
Upper Upright	212	96
Tower Boom	515	234
Lower Upright	100	45
Tower Link	150	68
Turntable	3560	1615
Engine Tray	890	404
Hydraulic Tray	225	102
Tail Counterweight	3410	1547
Bolt-on T/T Cwt. (AJ)	487	221
Chassis (12x16.5 pneu. tires)	4200	1905
12x16.5 pneu. Tire & Wheel	130	59
12x16.5 F/F Tire & Wheel	305	138
33/15.5x16.5 pneu. Tire & Wheel	150	68
33/15.5x16.5 F/F Tire & Wheel	374	170
33/16LL x 16.1 pneu Tire & Wheel	91.5	41.5
33/16LL x 16.1 F/F Tire & Wheel	426	193.4

1.9CRITICAL STABILITY WEIGHTS

Table 1-6.Critical Stability Weights

Component	LB.	KG.
Ford Engine	339	154
Deutz Engine	441	200
Isuzu Engine	389	176
6 ft Platform	160	73
5 ft. Platform	145	66
4 ft. Platform	130	59
Bolt-on T/T Cwt. (AJ)	487	221
12x16.5 pneu. Tire & Wheel	130	59
12x16.5 F/F Tire & Wheel	305	138
33/15.5x16.5 pneu. Tire & Wheel	150	68
33/15.5x16.5 F/F Tire & Wheel	374	170
33/16LL x 16.1 pneu Tire & Wheel	91.5	41.5
33/16LL x 16.1 F/F Tire & Wheel	426	193.4

1.10 CYLINDER SPECIFICATIONS

Table 1-7.Cylinder Specifications

Cylinder	Bore	Stroke	Rod Dia.
Oscillation	2.5 in.	4.125 in.	1.75 in.
	(63.5 mm)	(104.8 mm)	(44.45 mm)
Lower Lift	4.5 in.	21.5 in.	2.5 in.
	(114.3 mm)	(546.1 mm)	(63.5 mm)
Mid Lift	4.0 in.	18.8 in.	2.0 in.
	(101.6 mm)	(479.5 mm)	(50.8 mm)
Upper Lift	3.5 in.	24.4 in.	2.5 in.
	(88.9 mm)	(619.4 mm)	(63.5 mm)
Telescope	2 in.	83.75 in.	1.25 in.
	(50.8 mm)	(2127.25 mm)	(31.75 mm)
Level	4.0 in.	10.9 in.	1.25 in.
	(101.6 mm)	(277.5 mm)	(31.75 mm)
Jib	3.0 in.	18.4 in.	1.5 in.
	(76.2 mm)	(467.4 mm)	(38.1 mm)
Rotate	1.5 in.	9.3 in.	0.75 in.
	(38.1 mm)	(236.2 mm)	(19 mm)

Updated 2-16-00

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1-3

SECTION 1 - SPECIFICATIONS

Figure 1-1. Lubrication Diagram

Updated 11-1-99

1-4

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3120869

SECTION 1 - SPECIFICATIONS

Table 1-8. Lubrication Chart

					Interval		Hours
	Components	Number/Type	Capacity	Lube					Comments
		Lube Points			3	6	1 Year	2 Years
					Months	Months	600 hrs	1200 hrs
					150 hrs	300 hrs
Lubrication
1	Swing Bearing - Internal	2 Grease Fitting	A/R	MPG	X
	Ball Bearing
2a	Swing Bearing - Teeth	Spray On	A/R	OGL	X				More frequent lubrication intervals may be
									required.
2b	End Bearings - Worm	2	A/R	MPG				X	Remove grease fittings and install plugs after
	Gear*								greasing.
3	Wheel Bearings (2WD	Repack	A/R	MPG				X
	Only)
4	Wheel Drive Hub	Level/Fill Plug	0.5 liters (1/2 full)	EPGL				X	Change after first 150 hours then every 1200
									hours of operation.
5	Hydraulic Return Filter	N/A	N/A	N/A		X			Change after first 50 hours and every 300
									hours thereafter or as indicated by condition
									indicator.
6	Hydraulic Charge Filter	N/A	N/A	N/A		X			Change after first 50 hours and every 300
									hours thereafter or as indicated by condition
									indicator.
7	Hydraulic Oil	Fill Cap	116 liters Tank	HO				X	Check level daily.
			124 liters System						Change every 1200 hours.
8	Suction Strainers (In Tank)	2	N/A	N/A				X	Remove and clean at time of hydraulic oil
									change.
9	Steer Cylinder	4	A/R	MPG	X
10	Oscillation Cylinders	2	A/R	MPG	X
Engines
11	Oil Change w/Filter - Ford	Fill Cap/Spin-on	5 Quarts (4.7 L)	EO	X				Check level daily; change every 150 hours.
		Element							Adjust final oil level by mark on dipstick.
12	Oil Change w/Filter - Deutz	Fill Cap/Spin-on	6 liters crankcase	EO	X				Check level daily; change every 600 hours.
		Element	**4. 5 liters cooler						Adjust final oil level by mark on dipstick.
13	Oil Change w/Filter - Isuzu	Fill Cap/Spin-on	5.6 liters crankcase	EO	X				Check level daily; change every 150 hours.
		Element	6.1 liters w/cooler						Adjust final oil level by mark on dipstick.
14	Fuel Filter - Ford	Replaceable	N/A	N/A			X
		Element
15	Fuel Filter - Deutz	Replaceable	N/A	N/A			X
		Element
16	Fuel Filter - Isuzu	Replaceable	N/A	N/A			X
		Element
17	Air Filter - Ford	Replaceable	N/A	N/A		X			Or as indicated by condition indicator
		Element
									Updated 11-1-99

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SECTION 1 - SPECIFICATIONS

Table 1-8. Lubrication Chart

						Interval		Hours
	Components	Number/Type	Capacity		Lube					Comments
		Lube Points				3	6	1 Year	2 Years
						Months	Months
								600 hrs	1200 hrs
						150 hrs	300 hrs
18	Air Filter - Deutz	Replaceable		N/A	N/A		X			Or as indicated by condition indicator
		Element
19	Air Filter - Isuzu	Replaceable		N/A	N/A		X			Or as indicated by condition indicator
		Element
NOTES:										KEY TO LUBRICANTS
Lubrication intervals are based on machine operation under normal conditions. For machines used in multi shift operations and/or exposed to hostile envi-									EO	Engine Oil
ronments or conditions, lubrication frequencies must be increased accordingly.									EPGL	Extreme Pressure Gear Lube
									HO	Hydraulic Fluid (Mobil DTE-11M)
* If necessary install grease fittings into worm gear housing and grease bearings.									MPG	Multi-Purpose Grease
									OGL	Open Gear Lubricant - Mobiltac 375 or
										equivalent

DO NOT OVERGREASE BEARINGS. OVERGREASING BEARINGS WILL RESULT IN

BLOWING OUTER SEAL IN HOUSING.

**When changing oil in the Deutz oil cooled engine, drain both the crankcase and the cooler. When refilling it is acceptable to overfill crankcase (10.5 L), capacity of both crankcase and cooler combined). Start engine, allow the engine to run until the thermostat opens (approximately 105 degrees C) cooler will fill up within minutes; shut down and wait for approximately two minutes. Check oil level, fill oil to max marking on dipstick.

Updated 11-1-99

1-6

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3120869

SECTION 1 - SPECIFICATIONS

1.11 FUNCTION SPEEDS (IN SECONDS)

450A

Main Boom Lift Up - 22-38

Main Boom Lift Down - 12-24

Tele In - 12-24

Tele Out - 20-32

Swing - 85-110

Rotate (Left & Right) - 16-25

450AJ

Main Boom Lift Up - 22-38

Main Boom Lift Down - 12-24

Tele In - 9-20

Tele Out - 14-30

Swing - 85-110

Rotate (Left & Right) - 16-25

E-A-R Up - 9-24

E-A-R Down - 12-24

1.12 SERIAL NUMBER LOCATION

A serial number plate is affixed to the left rear side of the frame. If the serial number plate is damaged or missing, the machine serial number is stamped on the left side of the frame.

xxxxxxx

SERIAL NUMBER	SERIAL NUMBER
PLATE	STAMPED ON FRAME

Figure 1-2. Serial Number Locations

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1-7

SECTION 1 - SPECIFICATIONS

UNPLATED CAP SCREWS

VALUES FOR ZINC PLATED BOLTS ONLY

UNBRAKO1960SERIES SOCKETHEADCAPSCREW	WITHLOC-WELPATCH	TORQUE	(asreceived)	NM
		CLAMPLOAD (KG)
8NUTS	TORQUE	(LOCTITE	)242OR271	NM
BOLTS8&GRADE		OR(DRY	263).LOC	NMNM NM
		(LOCTITE	262)
		(LUB.)
SAEGRADE
	CLAMP	LOAD (KG)
2NUTS	TORQUE	(LOCTITE	)242OR271	NM
BOLTS5&GRADE		OR(DRY	263).LOC	NMNM NM
		(LOCTITE	262)
		(LUB.)
SAEGRADE
	CLAMP	LOAD (KG)
THREAD	STRESS AREA		(SQ.CM)
BOLT DIA. (CM)
	THD
	SIZE

1 1 2 2
2 2 3 3
245	272	372	417

1 1		2	2
1 1		2	2
172	191	263	277
0.0153	0.0168	0.0232	0.0258
0.2845		0.3505
40		32		40
	48
4		6

4 4
5 5
572	599

3 3
4 4
408	426
0.0356	0.0374
0.4166
32
	36
8

5 6
7 8
717	817

4 4
5 6
508	583
0.0445	0.0508
0.4826
24
	32
10

18	19
1442	1651
18	21

12	14
16	19
1297	1488
12	16

9	10
11	14
916	1052
0.0808	0.0925
0.6350
20
	28
1/4

34	37		61	68		95	102		149	156		210	224
2377	2631		3493	3983		4822	5384		6437	7253		8256	9208
41	41		68	75		109	122		163	183		224	258
30	34		54	61		85	95		130	146		188	209
25	27		48	48		75	81		109	122		149	176
34	34		61	68		95	109		149	163		204	231
2141	2821		3175	3583		4332	4854		5783	6532		7539	8278
26	29		48	54		75	81		115	136		163	183
22	23		38	43		61	68		92	108		133	148
18	19		31	34		48	68		75	88		109	122
23	26		41	48		68	75		102	122		149	163
1515	1678		2241	2540		3085	3425		4105	4854		5262	5874
0.1331	0.1473		0.1969	0.2230		0.2700	0.3015		0.3604	0.4061		0.4623	0.5156
0.7938			0.9525			1.1112			1.2700			1.4288
18		24	16		24	14		20	13		20	12
													18
5/16			3/8			7/16			1/2			9/16

285	298
10251	11612
326	359
244	277
231	244
298	326
9231	10433
224	258
183	207
149	176
204	231
6532	7394
0.5740	0.6502
1.5875
11
	18
5/8

495	542	793	861
15150	16919	20956	23088
570	631	895	983
408	456	658	724
380	434	624	678
515	570	814	895
13653	15241	18870	20775
387	448	644	705
325	363	523	576
271	298	434	475
353	407	583	637
9662	10796	13336	14697
0.8484	0.9474	1.1735	1.2929
1.9050		2.2225
10		9
	16		14
3/4		7/8

1173	1241
27488	30074
1342	1492
931	1079
922	1003
1220	1356
23360	27080
915	997
785	858
651	719
868	949
17509	19142
1.5392	1.6840
2.5400
8
	12
1

1681	1871		2373	2549		3145	3308		4122	4433
34610	38828		43954	48671		52391	59648		63731	71669
1898	2136		2712	2983		3559	4068		4712	5322
1396	1566		1970	2183		2586	2935		3430	3856
1302	1464		1844	2034		2413	2766		3200	3607
1736	1953		2468	2712		3227	3688		4284	4827
31162	34927		38554	43818		47174	53570		57380	142200
1139	1254		1593	1762		2068	2373		2746	3118
968	1087		1368	1516		1792	2042		2379	2676
814	895		1139	1247		1492	1708		1980	2224
1085	1193		1519	1681		1980	2278		2630	2983
19187	21546		24404	27035		29076	33113		35381	39781
1.9380	2.1742		2.4613	2.7254		2.9337	3.3401		3.5687	4.0132
2.8575			3.1750			3.4925			3.8100
7		12	7		12	6		12	6
										12
1-1/8			1-1/4			1-1/2			1-1/2

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

SAE GRADE 5 SAE GRADE 8

Figure 1-3. Torque Chart

1-8

– JLG Lift –

3120869

SECTION 2 - PROCEDURES

SECTION 2. PROCEDURES

2.1GENERAL

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.

2.2SERVICE AND 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

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.

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 compo-

nent 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.

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Bearings

Hydraulic System

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.

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 Torque Chart Section 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.

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 the Lubrication Chart in Section 1.

2.3 LUBRICATION AND 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 the Lubrication Chart in Section 1. Always examine filters for evidence of metal particles.

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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.

Hydraulic Oil

1.Refer to Section 1 for recommendations for viscosity ranges.

2.JLG recommends Mobilfluid 424 hydraulic oil, which has an SAE viscosity of 10W-30 and a viscosity index of 152.

NOTE: Start-up of hydraulic system with oil temperatures below -26 degrees C (-15 degrees F) 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 -26 degrees C (-15 degrees F).

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 -29 degrees C (-20 degrees F). However, use of this oil will give poor performance at temperatures above49 degrees C (120 degrees F). Systems using DTE 11 oil should not be operated at temperatures above 94 degrees C (200 degrees F) 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 50 hours of operation and every 300 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 contami-

nants 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 Section 1 for an explanation of the lubricant key designations appearing in the Lubrication Chart.

2.4CYLINDERS - THEORY OF OPERATION

Systems Incorporating Double Acting

Cylinders

Cylinders are of the double acting type. Systems incorporating double acting cylinders are as follows: Slave Level, Master Level, Lift, Telescope, Axle Lockout and Steer. 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 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.

Systems Incorporating Holding Valves

Holding valves are used in the - Lift, Telescope, Lockout, and Slave Level 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.

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2.5 VALVES - THEORY OF OPERATION		2.6 BOOM MAINTENANCE
	Solenoid Control Valve

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 consist 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 spring loaded to center position, therefore when the control is released, the spool automatically returns to neutral, prohibiting any flow through the circuit.

Relief Valves

Relief valves are installed at various points within 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.

IF PERFORMING MAINTENANCE ON THE BOOM, DO NOT USE A LIFTING DEVICE TO LIFT THE BOOMS UNLESS THE HOLDING

VALVES HAVE BEEN REMOVED FIRST. FAILURE TO DO SO WILL

RESULT IN SEVERE DAMAGE TO THE BOOM.

Removal of the Boom Assembly

1.Remove the platform and platform support as follows:

a.Disconnect electrical cable from control console.

b.Tag and disconnect the hydraulic lines running to the rotate cylinders. Cap the hydraulic lines and ports.

c.Using an overhead crane or suitable lifting device, use nylon support straps to support the platform/support.

NOTE: When removing the retaining pin from the rod end of the level cylinder, make sure the cylinder is properly supported.

d.Remove bolts and keeper pins that secures the retaining pins. Using a suitable brass drift and hammer, remove the retaining pins from the platform support.

LIFT CYLINDER

PIVOT PIN

BOOM

PIVOT

LEVEL

LINK

PIVOT

Figure 2-1. Location of Components - Boom Removal

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2.Remove the boom from the turntable as follows:

a.Disconnect wiring harness from ground control harness connector.

g.Using all applicable safety precautions, carefully lift boom assembly clear of turntable and lower to ground or suitable supported work surface.

Disassembly of the Main Boom

HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-

ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF CONTAMINANTS INTO SYSTEM.

b.Tag and disconnect hydraulic lines from boom to control valve. Use a suitable container to retain any residual hydraulic fluid. Cap all hydraulic lines and ports.

1.Loosen jam nuts on aft end of fly boom wear pad adjustment and loosen adjustments.

2.Using a portable power source, attach hose to telescope cylinder port block. Using all applicable safety precautions, activate hydraulic system and extend cylinder to gain access to cylinder rod retaining pin. Shut down hydraulic system.

c.Using a suitable lifting equipment, adequately support boom weight along entire length.

d.Remove the bolts and keeper pins securing the lift cylinder pivot pin. Using a suitable brass drift and hammer, remove the pivot pin from the lower boom.

NOTE: To gain access for removal of the pivot pins, it may be necessary to remove the ground control box, hydraulic and fuel tanks, and the counterweight.

e.Remove hardware securing the level link pivot pin. Using a suitable brass drift and hammer, remove the pin from the level link and turntable.

f.Remove hardware securing the lower boom pivot pin. Using a suitable brass drift and hammer, remove pin from the turntable.

3.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 initial discharge, there should be no further leakage from the retract port.

4.Remove hardware securing telescope cylinder to the fly boom section, then remove pin from fly.

5.Remove hardware securing telescope cylinder to the base boom section.

WHEN REMOVING TELESCOPE CYLINDER FROM BOOM SECTIONS. CARE SHOULD BE TAKEN NOT TO LEAVE CYLINDER REST ON POWERTRACK WHICH COULD CAUSE DAMAGE TO

POWERTRACK.

FLY BOOM

RETAINING RING

RETAINING RING

BASE BOOM

TELESCOPE CYLINDER

Figure 2-2. Location of Components - Removal of Telescope Cylinder

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6.Using a suitable lifting device, remove telescope cylinder from boom sections.

7.Using a piece of tape, mark the length of hoses and wires from front of fly boom and bottom of base boom for reassembly.

8.Remove hardware securing the front wear pads on base boom section, remove wear pads.

Figure 2-3. Location of Components - Front Wear Pads

9.Remove hardware securing the powertrack to the aft end of the fly boom section.

10.Using a suitable lifting device, remove fly boom from boom section.

11.Remove hydraulic lines and electrical cables from powertrack.

12.Remove hardware securing powertrack to the base boom section. Remove powertrack.

Inspection

1.Inspect all boom pivot pins for wear, scoring or other damage, and for tapering or ovality. Replace pins as necessary.

2.Inspect lift cylinder pins for wear, scoring or other damage, and for tapering or ovality. Ensure pin surfaces are protected prior to installation. Replace pins as necessary.

3.Inspect telescope cylinder rod attach pin for wear, scoring or other damage. Replace pin as necessary.

4.Inspect inner diameter of boom pivot bushings for scoring, distortion, wear or other damage. Replace bushings as necessary.

5.Inspect wear pads for wear.

6.Inspect all threaded components for damage such as stretching, thread deformation, or twisting. Replace as necessary.

7.Inspect structural units of boom assembly for bending, cracking, separation of welds, or other damage. Replace boom sections as necessary.

Assembly of the Main Boom

1.Install power track to the attach point on the base boom section. Secure power track with the attaching hardware.

2.Install hydraulic lines and electrical cables into the power track.

3.Install wear pads to the aft end of the fly section.

4.Using suitable lifting equipment, slide fly section into the base section until power track attach point aligns with holes in side of base section.

5.Attach the power track to the aft end of fly boom section. Secure power track with the attaching hardware.

6.Using suitable lifting equipment, slide fly boom section out to gain access to telescope cylinder attach pin hole.

7.Measure the distance between the telescope cylinder port block attach point on base boom section and the attach point on fly boom section.

8.Connect a suitable auxiliary hydraulic power source to the telescope cylinder port block.

9.Extend the telescope cylinder the distance of the two attach points.

10.Secure the sling and lifting device at the telescope cylinder’s approximate center of gravity, and lift the cylinder to the aft end of the boom assembly.

WHEN INSERTING THE TELESCOPE CYLINDER INTO THE BOOM, CARE MUST BE TAKEN NOT TO DAMAGE THE POWER TRACK

ASSEMBLY.

11.Slowly slide the telescope cylinder into boom assembly, align rod end with attach point in fly section. Insert pin and secure with retaining ring.

12.Align bolt holes at aft end of base boom section with telescope cylinder port block. Secure telescope cylinder with hardware.

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13.Install wear pads at end of base boom section. Using shims, adjust the adjustable wear pads to zero clearance. Adjust pads alternately side to side, so that fly boom section is centered in base boom section.

14.Retract boom section fully. Using shims, adjust wear pads at aft end of boom section to zero clearance. Adjust pads alternately side to side, so that fly boom section is centered in base boom section.

15.Disconnect auxiliary power source from telescope cylinder.

Installation of the Boom Assembly

1.Using suitable lifting equipment, position boom assembly on turntable so that boom pivot holes in both boom and turntable are aligned.

2.Install boom pivot pin, ensuring that location of the hole in pivot pin aligns with attach point on upright.

2.7DRIFT 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

3.Using all applicable safety precautions, operate lift- AREAS ABOVE AND BELOW BOOM AND PLATFORM AND AHEAD ing equipment in order to position boom lift cylinder OF PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PER-

and level link so that holes in cylinder rod end and level link are aligned with the one in the turntable. Insert cylinder pins.

4.If necessary, gently tap pins into position with a soft headed mallet, ensuring that attach holes in pins are aligned with attach holes in boom structure. Secure with hardware.

5.Connect all hosing and wiring.

6.Install the platform to the boom assembly.

7.Connect all hosing and wiring at platform control station.

8.Using all safety precautions, operate machine systems and extend and retract boom for four or five cycles.

9.Shut down machine systems and check for leakage.

SONNEL.

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

3.Position TELESCOPE control switch to OUT and hold until boom extends approximately 1.2 meters (4 feet); 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.

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8.Position LIFT control switch to DOWN and hold until boom reaches horizontal; check boom length against measurement. If boom has retracted more than 2.5 cm (1 inch) and oil is leaking around rodend of telescope cylinder (check with light and inspection mirror), seals are defective and require 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 2 meters (6 feet) 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 OBSTRUC-

TIONS AND PERSONNEL.

3.With boom fully retracted, place LIFT control switch to UP and hold until platform is approximately 2 meters (6 feet) 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 7.5 cm (3 inches).

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.

2.8CYLINDER CHECKING PROCEDURE

IF PERFORMING MAINTENANCE ON THE BOOM CYLINDERS, DO NOT USE A LIFTING DEVICE TO LIFT THE BOOMS UNLESS THE HOLDING VALVES HAVE BEEN REMOVED FIRST. FAILURE TO DO

SO WILL RESULT IN SEVERE DAMAGE TO THE BOOM.

NOTE: Cylinder check must be performed anytime a system component is replaced or when improper system operation is suspected.

Cylinders Without Counterbalance Valves -

Master Cylinder and Steer Cylinder

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

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

3.Activate engine and extend cylinder.

4.If cylinder retract port leakage is less than 6-8 drops per minute, carefully reconnect hose to port and retract cylinder. If leakage continues at a rate of 6-8 drops per minute or more, cylinder repair must be made.

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

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

7.If extend port leakage is less than 6-8 drops per minute, carefully reconnect hose to extend port, than activate cylinder through one complete cycle and check for leaks. If leakage continues at a rate of 6-8 drops per minute or more, cylinder repairs must be made.

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Cylinders With Dual Counterbalance Valves -

Slave Level, Lift, and Telescope

OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION ONLY.

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

IF WORKING ON THE PLATFORM LEVEL CYLINDER, STROKE

PLATFORM LEVEL CYLINDER FORWARD UNTIL PLATFORM SITS

AT A 45 DEGREES ANGLE.

2.Shut down hydraulic system and allow machine to sit for 10-15 minutes. If machine is equipped with bang-bang or proportional control valves, turn IGNITION SWITCH to ON, move control switch or lever for applicable cylinder in each direction, then turn IGNITION SWITCH to OFF. If machine is equipped with hydraulic control valves, move control lever for applicable cylinder in each direction. This is done to relieve pressure in the hydraulic lines. Carefully remove hydraulic hoses from appropriate cylinder port block.

3.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 ports. If leakage continues at a rate of 6-8 drops per minute or more, the counterbalance valve is defective and must be replaced.

4.To check piston seals, carefully remove the counterbalance valve from the retract port. After initial discharge, there should be no 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.

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

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

2.9CYLINDER REPAIR

NOTE: The following are general procedures that apply to all of the cylinders on this machine. Procedures that apply to a specific cylinder will be so noted.

Disassembly

DISASSEMBLY OF THE CYLINDER SHOULD BE PERFORMED ON

A CLEAN WORK SURFACE IN A DIRT FREE WORK AREA.

1.Connect a suitable auxiliary hydraulic power source to the cylinder port block fitting.

DO NOT FULLY EXTEND CYLINDER TO THE END OF STROKE.

RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRES-

SURE.

2.Operate the hydraulic power source and extend the cylinder. Shut down and disconnect the power source. Adequately support the cylinder rod, if applicable.

3.If applicable, remove the cartridge-type holding valve and fittings from the cylinder port block. Discard o-rings.

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Figure 2-4. Boom Prop Configuration

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4. Place the cylinder barrel into a suitable holding fix-	7. Attach a suitable pulling device to the cylinder rod
ture.	port block end or cylinder rod end, as applicable.
	EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYL-
	INDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
	CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
	CYLINDER BARREL SURFACES.
	8. With the barrel clamped securely, apply pressure to
	the rod pulling device and carefully withdraw the
	complete rod assembly from the cylinder barrel.

Figure 2-5. Cylinder Barrel Support

5.Mark cylinder head and barrel with a center punch for easy realignment. Using an allen wrench, loosen the cylinder head retainer cap screws, and remove cap screws from cylinder barrel.

Figure 2-6. Capscrew Removal

NOTE: Steps 6 applies only to the lower lift and telescope cylinders.

6.Using a spanner wrench, loosen the end cap or head retainer, and remove from cylinder barrel.

Figure 2-7. Cylinder Rod Support

9.Using suitable protection, clamp the cylinder rod in a vise or similar holding fixture as close to the piston as possible.

10.Loosen and remove the cap screw(s), if applicable, which attach the tapered bushing to the piston.

11.Insert the cap screw(s) in the threaded holes in the outer piece of the tapered bushing. Progressively tighten the cap screw(s) until the bushing is loose on the piston.

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12. Remove the bushing from the piston.

Figure 2-8. Tapered Bushing Removal

13.Screw the piston CCW, by hand, and remove the piston from cylinder rod.

14.Remove and discard the piston o-rings, seal rings, and backup rings.

15.Remove piston spacer, if applicable, from the rod.

16.Remove the rod from the holding fixture. Remove the cylinder head gland and retainer plate, if applicable. Discard the o-rings, back-up rings, rod seals, and wiper seals.

Cleaning and Inspection

1.Clean all parts thoroughly in an approved cleaning solvent.

2.Inspect the cylinder rod for scoring, tapering, ovality, or other damage. If necessary, dress rod with Scotch Brite or equivalent. Replace rod if necessary.

3.Inspect threaded portion of rod for excessive damage. Dress threads as necessary.

4.Inspect inner surface of cylinder barrel tube for scoring or other damage. Check inside diameter for tapering or ovality. Replace if necessary.

5.Inspect threaded portion of barrel for damage. Dress threads as necessary.

6.Inspect piston surface for damage and scoring and for distortion. Dress piston surface or replace piston as necessary.

7.Inspect threaded portion of piston for damage. Dress threads as necessary.

8.Inspect seal and o-ring grooves in piston for burrs and sharp edges. Dress applicable surfaces as necessary.

9.Inspect cylinder head inside diameter for scoring or other damage and for ovality and tapering. Replace as necessary.

10.Inspect threaded portion of head for damage. Dress threads as necessary.

11.Inspect seal and o-ring grooves in head for burrs and sharp edges. Dress applicable surfaces as necessary.

12.Inspect cylinder head outside diameter for scoring or other damage and ovality and tapering. Replace as necessary.

13.If applicable, inspect rod and barrel bearings for signs of correct excessive wear or damage. Replace as necessary.

a.Thoroughly clean hole, (steel bushing) of burrs, dirt etc. to facilitate bearing installation.

b.Inspect steel bushing for wear or other damage. If steel bushing is worn or damaged, rod/barrel must be replaced.

c.Lubricate inside of the steel bushing with WD40 prior to bearing installation.

d.Using an arbor of the correct size, carefully press the bearing into steel bushing.

NOTE: Install pin into the Gar-Max bearing dry. Lubrication is not required with nickel plated pins and bearings.

Figure 2-9. Gar-Max Bearing Installation

14.Inspect travel limiting collar or spacer for burrs and sharp edges. If necessary, dress inside diameter surface with Scotch Brite or equivalent.

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15.If applicable, inspect port block fittings and holding valve. Replace as necessary.

16.Inspect the oil ports for blockage or the presence of dirt or other foreign material. Repair as necessary.

17.If applicable, inspect piston rings for cracks or other damage. Replace as necessary.

Assembly

NOTE: Prior to cylinder assembly, ensure that the proper cylinder seal kit is used. See your JLG Parts Manual.

Apply a light film of hydraulic oil to all components prior to assembly.

1.A special tool is used to install a new rod seal into the applicable cylinder head gland groove.

Figure 2-10. Rod Seal Installation

WHEN INSTALLING "POLY-PAK" PISTON SEALS, ENSURE SEALS

ARE INSTALLED PROPERLY. REFER TO WIPER SEAL INSTALLA-

TION FOR CORRECT SEAL ORIENTATION. IMPROPER SEAL INSTALLATION COULD RESULT IN CYLINDER LEAKAGE AND IMPROPER CYLINDER OPERATION.

2.Use a soft mallet to tap a new wiper seal into the applicable cylinder head gland groove. Install a new wear ring into the applicable cylinder head gland groove.

Figure 2-11. Wiper Seal Installation

3.Place a new o-ring and back-up seal in the applicable outside diameter groove of the cylinder head.

Figure 2-12. Installation of Head Seal Kit

4.Install washer ring onto rod, carefully install the head gland on the rod, ensuring that the wiper and rod seals are not damaged or dislodged. Push the head along the rod to the rod end, as applicable.

5.Carefully slide the piston spacer on the rod.

6.If applicable, correctly place new o-ring in the inner piston diameter groove. (The backup ring side facing the O-ring is grooved.)

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SECTION 2 - PROCEDURES

7.If applicable, correctly place new seals and guide lock rings in the outer piston diameter groove. (A tube, with I.D. slightly larger than the O.D.of the piston is recommended to install the solid seal.)

NOTE: The backup rings for the solid seal have a radius on one side. This side faces the solid seal.(See magnified insert in Figure 2-13.)The split of seals and backup rings are to be positioned so as not to be in alignment with each other.

Figure 2-13. Piston Seal Kit Installation

8.Using suitable protection, clamp the cylinder rod in a vise or similar holding fixture as close to piston as possible.

9.Carefully thread the piston on the cylinder rod hand tight, ensuring that the o-ring and back-up rings are not damaged or dislodged.

10.Thread piston onto rod until it abuts the spacer end and install the tapered bushing.

NOTE: When installing the tapered bushing, piston and mating end of rod must be free of oil.

WHEN REBUILDING THE STEER, AXLE OSCILLATION, LOWER LIFT, LEVEL CYLINDER, UPPER LIFT CYLINDER, OR E.A.R. CYLINDERS, APPLY LOCTITE #242 TO TAPERED BUSHING BOLTS,

THEN TIGHTEN SECURELY. (SEE TABLE 2-1 AND 2-2. TORQUE

SPECIFICATIONS).

11.Assemble the tapered bushing loosely into the piston and insert JLG capscrews (not vendor capscrews) through the drilled holes in the bushing and into the tapped holes in the piston.

Figure 2-14. Tapered Bushing Installation

12.Tighten the capscrews evenly and progressively in rotation to the specified torque value. (See Table 2-1, Cylinder Head and Tapered Bushing Torque Specifications.)

13.After the screws have been torqued, tap the tapered bushing with a hammer (500 to 750 gram) and brass shaft (approximately 19 mm in diameter) as follows;

a.Place the shaft against the cylinder rod and in contact with the bushing in the spaces between the capscrews.

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