JLG 15VPSP Service Manual

Service and Maintenance Manual

Model

15VPSP

3120797

February 26, 2001

ANSI

FOREWORD

The purpose of this manual is to provide users with the operating procedures essential for the promotion of
proper machine operation for its intended purpose. It is important to over-stress proper machine usage. All
information in this manual should be READ and UNDERSTOOD before any attempt is made to operate the
machine. YOUR OPERATING MANUAL IS YOUR MOST IMPORTANT TOOL - Keep it with the machine.

REMEMBER ANY EQUIPMENT IS ONLY AS SAFE AS THE OPERATOR.

BECAUSE THE MANUFACTURER HAS NO DIRECT CONTROL OVER MACHINE APPLICATION AND
OPERATION, PROPER SAFETY PRACTICES ARE THE RESPONSIBILITY OF THE USER AND HIS OPER­ATING PERSONNEL.

ALL INSTRUCTIONS IN THIS MANUAL ARE BASED ON THE USE OF THE MACHINE UNDER PROPER
OPERATING CONDITIONS, WITH NO DEVIATIONS FROM THE ORIGINAL DESIGN. ALTERATION AND/
OR MODIFICATION OF THE MACHINE IS STRICTLY FORBIDDEN, WITHOUT WRITTEN APPROVAL
FROM JLG INDUSTRIES, PER OSHA REGULATIONS.

THIS "SAFETY ALERT SYMBOL" IS USED TO CALL ATTENTION TO POTENTIAL HAZARDS
WHICH MAY LEAD TO SERIOUS INJURY OR DEATH IF IGNORED.

Safety of personnel and proper use of the machine are of primary concern, DANGER, WARNING, CAUTION,
IMPORTANT, INSTRUCTIONS and NOTE are inserted throughout this manual to emphasize these areas.

They are defined as follows:

DANGER INDICATES AN IMMINENTLY HAZARDOUS SITUA­TION WHICH, IF NOT AVOIDED WILL RESULT IN SERIOUS
INJURY OR DEATH.

WARNING INDICATES A POTENTIALLY HAZARDOUS SITU­ATION WHICH, IF NOT AVOIDED COULD RESULT IN SERI­OUS INJURY OR DEATH.

IMPORTANT

CAUTION INDICATES A POTENTIALLY HAZARDOUS SITUA­TION WHICH, IF NOT AVOIDED, MAY RESULT IN MINOR OR
MODERATE INJURY. IT MAY ALSO BE USED TO ALERT
AGAINST UNSAFE PRACTICES.

Also in this Manual "Notes:" are used to provide infor­mation of special interest.

JLG INDUSTRIES, INC. MAY HAVE ISSUED SAFETY RELATED BULLETINS FOR YOUR JLG PRODUCT. CONTACT JLG INDUS­TRIES, INC. OR THE LOCAL AUTHORIZED JLG DISTRIBUTOR FOR INFORMATION CONCERNING SAFETY RELATED BULLE­TINS WHICH MAY HAVE BEEN ISSUED FOR YOUR JLG PRODUCT. ALL ITEMS REQUIRED BY THE SAFETY RELATED
BULLETINS MUST BE COMPLETED ON THE AFFECTED JLG PRODUCT.

IMPORTANT OR INSTRUCTIONS PROCEDURES ESSENTIAL
FOR SAFE OPERATION AND WHICH, IF NOT FOLLOWED
MAY RESULT IN A MALFUNCTION OR DAMAGE TO THE
MACHINE.

Due to the continuous product improvements, JLG Industries, Inc. reserves the right to make specification changes without
prior notification. Contact JLG Industries, Inc. for updated information.

This page left intentionally blank.

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

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 established by a qualified person and 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 machine
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 component weight and 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 IS THE RESPONSIBILITY OF THE OWNER/
OPERATOR.

C. MAINTENANCE

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

• 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 DANGER, WARNING, CAU­TION AND OTHER INSTRUCTIONS ON MACHINE
AND IN SERVICE MANUAL.

• KEEP STANDING SURFACES AND HAND HOLDS
FREE OF OIL, GREASE, WATER, ETC.

• NEVER WORK UNDER AN ELEVATED PLATFORM
UNTIL PLATFORM HAS BEEN SAFELY RESTRAINED
FROM ANY MOVEMENT BY BLOCKING OR OVER­HEAD SLING.

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

•BATTERY SHOULD ALWAYS BE DISCONNECTED
DURING REPLACEMENT OF ELECTRICAL COMPO­NENTS.

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

• USE ONLY APPROVED, NONFLAMMABLE CLEANING
SOLVENTS.

B. HYDRAULIC SYSTEM SAFETY

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

2. Relieve system pressure by activating the lift DOWN
control with the platform completely lowered to
direct any line pressure back into the return line to
the reservoir. Pressure feed lines to system compo­nents can then be disconnected with minimal fluid
loss.

3120797 – JLG Lift – a

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

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b – JLG Lift – 3120797

EFFECTIVITY CHANGES

February 28, 2000 – Original Issue of Manual
October 19, 2000 – Revised – Complete Manual
November 15, 2000 – Revised – Pages Affected: Section 1 - Pages 1-1 & 1-2

Section 2 - Pages 31 & 32.

February 26, 2001 – Revised – Pages Affected: Section 3 - Pages 3-8 & 3-9.

EFFECTIVITY PAGE

3120797 – JLG Lift – c

EFFECTIVITY PAGE

This Page Left Intentionally Blank

d – JLG Lift – 3120797

TABLE OF CONTENTS

SUBJECT - SECTION, PARAGRAPH PAGE NO.

SECTION INTRODUCTION - - MAINTENANCE SAFETY PRECAUTIONS

A GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a

B HYDRAULIC SYSTEM SAFETY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a

C MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a

EFFECTIVITY CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .c

SECTION 1 - SPECIFICATIONS

1.1 Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.2 Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.3 Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

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

1.5 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.6 Hydraulic Pressure Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.7 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1.8 Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

SECTION 2 - SERVICE PROCEDURES

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

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

2.3 Lubrication Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.4 Positioning Lift For Access To Components Located Under The Base Frame . . . . . . . . . . . . . . .2-4

2.5 Drive Motor Component Service Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

2.6 Platform Control Box Service Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

2.7 Battery Charger Assembly And Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-20

2.8 Mast Assembly And Disassembly Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2.9 Mast To Base Frame Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-30

2.10 Mast Chains/Cables And Sequencing Cables Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-31

2.11 Sequence Cable Replacement Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-33

2.12 Preventive Maintenance And Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35

SECTION 3 - TROUBLESHOOTING

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

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

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

3.4 Electrical Circuit Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.5 Troubleshooting Section - Table Of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11

3.6 Ohm Ratings For Various Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

3.7 Main Power Circuit Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13

3.8 Drive Train Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16

3.9 Mast Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-26

3.10 Hydraulic Leak Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-37

3.11 Base Frame Components Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-38

3120797 – JLG Lift – i

TABLE OF CONTENTS

(Continued)

LIST OF FIGURES

FIGURE NO. TITLE PAGE NO.

1-1. Hydraulic Pressure Setting - Adjustment Screw Located at Base of Pump Motor . . . . . . . . . . . .1-4

1-2. Hydraulic Pressure Gauge Installation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1-3. Lubrication Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1-4. Torque Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

2-1. Accessing Machine Underside Components by Lifting with a Fork Truck. . . . . . . . . . . . . . . . . . .2-4

2-2. Check Torque Limit Clutch - Torque Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

2-3. Torque Limit Clutch - Adjustment Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2-4. Brake Assembly Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-5. Brake Armature Plate & Brake Disk Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2-6. Manual Release Brake Cable Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-7. Drive Motor Assembly Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-8. Drive Motor Gear Box Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2-9. Gear/Pinion Shaft Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

2-10. Drive Shaft Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2-11. Drive Motor Brush Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2-12. Drive Motor Brush Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2-13. Correct/Incorrect Brush Spring Bracket Positions.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

2-14. Platform Control Box Assembly (Exploded View). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15

2-15. Platform Control - Circuit Board Component Wiring Connections. . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2-16. Mast Section - Assembly Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2-17. 15VPSP Mast Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-26

2-18. Mast Chain Routing Diagram.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27

2-19. Mast Chain/Cable/Sequence Cable Adjustment Components. (Typical) . . . . . . . . . . . . . . . . . . .2-32

3-1. LED Battery/Fault Code Indicator Strip on Platform Controller Box. . . . . . . . . . . . . . . . . . . . . . . .3-2

3-2. Overview of Standard Electrical System. (Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-3. VP Electrical Diagram. (VP Series - Standard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8

3-4. Hydraulic Diagram. (VP Series) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

LIST OF TABLES

TABLE NO. TITLE PAGE NO.

1-1. Machine GVW and Wheel Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-2 Machine Interlock Switch Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-3. Hydraulic Oil Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-4. Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-5. Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1-6 Lubrication Intervals for Various Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

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

2-2 VPSP Mast Component Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2-3 Preventive Maintenance & Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-36

3-1 MC-1 WARNING CODES (Indicated by 3 beeps, then slow flashing LED’s). . . . . . . . . . . . . . . . .3-3

3-2 MC-1 ERROR CODES (Indicated by rapid LED flashing and periodic beep) . . . . . . . . . . . . . . . .3-4

3-3 Ohm Ratings for Various Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

3-4 Unit will not Power Up From Ground Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

3-5 No Power At Platform Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14

3-6 Won’t Drive. (Platform Lowered or Elevated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16

3-7 Elevation Switch Circuit Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16

3-8 Brake Limit Switch Circuit Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17

3-9 Drive Motor/Circuit Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17

3-10 Brake Switch/Circuit Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17

3-11 Won’t Drive with Platform Elevated. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-18

3-12 Tilt Sensor Circuit Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-18

3-13 PHP Limit Switch Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19

ii – JLG Lift – 3120797

3-14 Won’t Climb Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-20

3-15 Drives In Opposite Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21

3-16 Only Drives A Short Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22

3-17 E-Stop and Key Switch Circuit Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-23

3-18 Won’t Drive Straight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24

3-19 Noise from Drive Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25

3-20 Platform Will Not Lift Up Using Platform Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-26

3-21 Pump Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27

3-22 Pump Valves Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-28

3-23 Platform Will Not Lower Using Platform Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-29

3-24 Unit Will Not Lift Up From Ground Control Toggle Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-30

3-25 Unit Will Not Lower From Ground Control Toggle Switch.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-31

3-26 Platform Will Not Lower Manually. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-32

3-27 Platform Lift Up and Down Jerky. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-33

3-28 Mast Noisy when Lifting and Lowering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-34

3-29 Platform (Mast) Won’t Stay Elevated. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-35

3-30 Platform (Mast) Descends Too Slowly.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-36

3-31 Hydraulic Leak Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-37

3-32 Caster Wheels Not Operating Freely. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-38

3-33 Pot Hole Protection (PHP) Bars Will Not Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-38

TABLE OF CONTENTS

3120797 – JLG Lift – iii

TABLE OF CONTENTS

(Continued)

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iv – JLG Lift – 3120797

SECTION 1 - SPECIFICATIONS

SECTION 1. SPECIFICATIONS

15VPSP

OPERATING SPECIFICATIONS

Maximum Occupants: . . . . . . . . . . . . . . . . . . . . . . . . . . 1 person

Maximum Work Load (Capacity):

Total platform capacity: . . . . . . . . . . . . . . . . . . . . . . . . 500 lb. (230 kg)

Maximum allowed on rear of platform: . . . . . . . . . . . . . 250 lb. (115 kg)

Maximum allowed on front of platform:. . . . . . . . . . . . . 250 lb. (115 kg)

Maximum Travel Grade (Gradeability): . . . . . . . . . . . . . 10%

(Platform stowed ONLY)

Maximum Travel Grade (Side Slope): . . . . . . . . . . . . . . 5° (Platform stowed ONLY)

Maximum Vertical Platform Height : . . . . . . . . . . . . . . . 15 ft. (4.57 m)

Maximum Horizontal Plat form Reach:. . . . . . . . . . . . . . 45.5 in. (115.5 cm) (F i xe d le ng t h of p la tf o r m)

Turning Radius (inside): . . . . . . . . . . . . . . . . . . . . . . . . 0.0 in. (0 cm)

Maximum Wheel Load: . . . . . . . . . . . . . . . . . . . . . . . . . 1090 lb. (484 kg) (Reference decal on chassis adjacent to each wheel)

Maximum Drive Speeds:

Platform Raised: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 mph

(reduced automa tically with limit switch)

Platform Stowed: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 mph

Maximum Platfor m Speeds:

Platform Up: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 seconds (w/max. rated load)

Platform Down:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 - 25 seconds (w/max. rated load)

Gross Machine Weight (Platform Empty): . . . . . . . . . . 2,190 lb. (995 kg) (See serial number plate for actual weight)

3120797 – JLG Lift – 1-1

SECTION 1 - SPECIFICATIONS

1.1 CAPACITIES

System Voltage

All VP Models –24 Volt DC (2 - 12 volt DC batteries)

Hydraulic Oil Reservoir

All VP Models – 5 qts. U.S. (4.7 ltr.)

1.2 COMPONENT DATA

Hydraulic Pump/Pump Motor Assembly

Pump Motor - 24 Volt DC motor Pump Displacement –

15VPSP – .098 cu. in./rev. (1.6cc/rev.)

Pump Output (Max.) –

15VPSP - 1.20 gpm @ 2200 psi Hydraulic System Pressure Setting – 15VPSP - 1000 psi (68.95 bar)

Rear Wheel Drive Motors

Drive Motors -

24 Volt DC w/perm. magnet Right angle gear Maintenance free sealed gear Brake shaft and drive shaft,Integral to Motor Parking Brake (must be released for pushing)

Batteries/Battery Charger

Batteries (2) – 12 Volt / 100 Amp Hour –

Deep CycleMarine - RV

Battery Charger –

U.S.A.. - 120 Volt A.C. / 60 Hz input

24 volt, 10 amp output - with 2 amp finish Reset Circuit Breaker Automatic Charge Circuit Plug Interlock Circuit

1.3 PERFORMANCE DATA

Platform Capacity

15VPSP –500 lbs. (230 kg) (250 lb. Front/250 lb. Rear)

Platform Size

15VPSP – 28 in. width x 48 in. length (71 cm) x (122 cm)

Machine Height (In Stowed Position)

15VPSP - 82 in. (2.08m) height

Machine Weight

15VPSP - 2,190 lb. (995 kg) (See Table 1. below)

Base Footprint

15VPSP - 32 in. (81 cm) width

52.5 in. (133 cm) length

Max. Platform Height (mast extended)

15VPSP –15 ft.(4.5m)

Platform Working Height (average)

15VPSP –21 ft.(6.4m)

Machine Drive Speed (max.)*

Plat. Lowered - 2 mph (3.22 kph)
Plat. Elevated - 0.5 mph (.81 kph)

(reduced by limit switch)

* Variable to maximum with speed cut back.

Amperage Draw (average)

Lift - 12 amps
Drive - 20 amps

1.4 TORQUE REQUIREMENTS

When maintenance becomes necessary or a fastener has
loosened, refer to the Torque Chart, Figure 1-3 to deter­mine proper torque value.

Table 1-1.

Machine GVW and Wheel Loads

VP MODEL CONFIG. GVW (no load)

15VPSP ANSI (U.S.) 2,190 lb. (995 k g) 1090 lb. (484 kg) 1090 lb. (484 kg)

DRIVE WHEEL

(ea) w/rated load

CASTER

(ea) w/rated load

1-2 – JLG Lift – 3120797

SECTION 1 - SPECIFICATIONS

Table 1-2. Machine Interlock Switch Operating Conditions.

Mast Elevation

mast retracted bars raised (not tilted) engaged Full Drive and Lift

mast retracted bars raised (not tilted) disengaged Drive and Lift Disabled
mast extended bars lowered (not tilted) engaged Drive 25% maximu m
mast extended bars raised (blocked) (not tilted) engaged Drive Disabled
mast extended bars lowered (tilt) engaged Drive and Lift disabled
mast retracted bars raised (tilt) engaged Lift Disabled

mast retracted

1.5 LUBRICATION

Hydraulic Oil

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 of 10W-30 and a viscosity index of 152.

For cold weather applications, i.e. when temperatures

remain consistently below +20°F (–7°C) JLG recom­mends using Mobil DTE 13 hydraulic oil.

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.

Table 1-3. Hydraulic Oil Operating Range

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)

50° F to 210° F

(+10° C to +210° C)

Drive Cutout

(PHP System)

bars raised/battery c harger

plugged-in

SAE VISCOSITY

GRADE

10W

10W-20, 10W-30

20W-20

Tilt Status Brake Status Controller Response

(not tilted) engaged Drive Disabled

Lubrication Specifications

Table 1-4. Lubrication Specifications

KEY SPECIFICATIONS

MPG - Multipurpose Grease having a minimum dripping point

of 350° F. Excelle nt water resistance and adhesive qual­ities, and being of extreme pressure type. (Timken OK
40 pounds minimum.)

EPGL - Extreme Pressure Gear Lube (oil) meeting API service

classification GL-5 or MIL-Spec MIL-L-2105.

HO - Hydraulic Oil. ISO-Vg grade 32, 46.

1.6 HYDRAULIC PRESSURE ADJUSTMENT

Adjust system pressure so that platform will raise with rated capacity in platform.

The following are recommended factory pressure set­tings;

15VPSP –1000 psi

Turning adjustment screw clockwise increases system

pressure, turning screw counterclockwise decreases
system pressure.

Make pressure adjustment with oil at normal operating
temperature. If pressure is set when oil is cold, platform
may not raise rated load after oil has warmed.

ONLY OPEN HYDRAULIC SYSTEM LINES WITH THE MAST LOW­ERED TO RELIEVE PRESSURE IN THE SYSTEM. CAREFULLY
LOOSEN REQUIRED FITTINGS, WEAR SAFETY PROTECTION
EQUIPMENT WHEN WORKING WITH HYDRAULIC SYSTEMS.

Connect pressure gauge as shown in Figure 1-2., Hydrau­lic Pressure Gauge Installation.

Select a T-Fitting to exactly match the thread size of the
pump (.562 x 18 THD), pressure line (.562 x 18 THD) and
gauge fitting as required.

3120797 – JLG Lift – 1-3

SECTION 1 - SPECIFICATIONS

PRESSURE

ADJUSTMENT

SCREW

ADJUSTMENT

SCREW CAP

RETURN

LINE

Figure 1-1. Hydraulic Pressure Setting - Adjustment

Screw Located at Base of Pump Motor

(Remove Hex Head Cap as Shown)

REPLACE ELBOW
WITH A T-FITTING

TO CONNECT

PRESSURE GAUGE

HERE

EXTEND

LINE

PRESSURE

GAUGE

Figure 1-2. Hydraulic Pressure Gauge Installation.

1.7 CYLINDER SPECIFICATIONS

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

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

Table 1-5. Cylinder Specifications

DESCRIPTION

15VPSP ­Lift Cylinder

BORE

in./(cm)

1.63

(4.14)

STROKE
in./(cm)

41.50

(105.41)

ROD DIA.

in./(cm)

1.38

(3.50)

1.8 SERIAL NUMBER LOCATIONS

For machine identification, a serial number plate is affixed
to the machine. The plate is located on the back of the
mast, just above the mast support bracket.

1-4 – JLG Lift – 3120797

SECTION 1 - SPECIFICATIONS

4

6

3

Figure 1-3. Lubrication Chart.

Table 1-6.Lubrication Intervals for Various Components

ITEM COMPONTENT

1 Hydraulic Oil

Drive Wheel

2

Bearings
Drive Wheel

3

Gear Box

4 Caster Axles 2 - Gr ease Fitting MPG - Pressure Gun
5 Swivel Raceways 2 - Front Casters M PG - Pressure Gun

6 Mast Chains * 2 - Per Section

* Applies Only to Mast Sections with Chains.

Key to Lubricants: MPG - Multipurpose Grease

NO/TYPE

LUBE POINTS

Fill To Line on
Reserv oir
5 Qt. Reservoir

4 - Grease Fittings MPG- Pressure Gun

2 - Gear Box Gear Oil

HO - Hydraulic Oil - See Section 1.5, "Lubrication" in Service Manual.
GEAR OIL - Good Quality Worm Gear Oil - SAE 90 - AGMA#5 - EP Compounded

LUBE/METHOD

HO - Check Hyd. Oil
L e ve l
HO - Change Hyd. Oil

Chain Lube - Brush or
Spray

1

2

5

INTERVAL HOURS

3
MONTHS
150 Hrs.

6
MONTHS
300 Hrs.

1

YEAR

600 Hrs.

2

YEARS

1200 Hrs.

✔

COMMENTS

Check Hydraulic Oil every 10 hrs.
Change Hydraulic Oil every 1200
hrs.

✔

Change only when serviced

requires 6 oz. (175 cc ’s) to fill.

✔
✔

✔

Inspect, lubricate if dry or r usting.

Notes: 1. Be cer tain to lubricate like items on each side of the machine.

2. Recommended lubricating intervals are based on nor mal use. If machine is subjected to severe operating conditions,

such as a high number of cycles, location, corrosive/dir ty environment, etc., user must adjust lubricating requirements accordingly.

3. Prior to checking hydraulic oil level, operate machine through one complete cycle of lift function (full up and down). Failure t o do s o wi l l
result in incorrect oil level reading on the hydraulic reservoir.

3120797 – JLG Lift – 1-5

SECTION 1 - SPECIFICATIONS

Figure 1-4. Torque Chart.

1-6 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

SECTION 2. SERVICE PROCEDURES

2.1 GENERAL

This section provides general information to assist in the
performance of maintenance on the personnel lift.
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.

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.

selves. As soon as a line or component is disconnected,
cap or cover all openings to prevent entry of foreign mat­ter.

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

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.

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.

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

Safety and Workmanship

Your safety, and that of others, is the first consideration
when engaging in the maintenance of equipment. Always
be conscious of component 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.

NEVER WORK UNDER AN ELEVATED PLATFORM UNTIL PLAT­FORM HAS BEEN SAFELY RESTRAINED FROM ANY MOVEMENT
BY BLOCKING OR OVERHEAD SLING.

Cleanliness

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 the wheel bearings, mast sec­tions and oil supply clean; however, these items must be
maintained on a scheduled basis in order to function
properly.

At any time when oil lines are disconnected, clear adja­cent areas as well as the openings and fittings them-

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

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.

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

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.

Lubricate new or used serviceable bearings before instal­lation. When pressing a bearing into a retainer or bore,

3120797 – JLG Lift – 2-1

SECTION 2 - SERVICE PROCEDURES

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

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.

Unless specific torque requirements are given within the
text, standard torque values should be used on heat­treated 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

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

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 and Servicing

Components and assemblies requiring lubrication and
servicing are shown in the Lubrication Chart, (See Figure
1-2.). 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.

Batteries

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

Mast Chain Inspection Procedure

MAST CHAINS TO BE INSPECTED AND LUBRICATED EVERY
THREE MONTHS.

Inspect mast chains for the following conditions: Wear: Always inspect that segment of chain that operates

over a sheave. As the chain flexes over the 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.

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 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. 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.

Table 2-1. Chain Stretch Tolerance

Chain Size

.50" pitch 12" or 24 pitches .24 in./12 in. spa n

.625 pitch 15" or 24 pitches . 30 in./15 in. span

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.

Pin to Pin

Measurement

Allowable Stretch

2-2 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

IMPORTANT

Tight Joints: All joints in the leaf chain should flex freely.
On leaf chain, tight joints are usually caused by rust/corro-

sion, or the inside plates “walking” off the bushing. Limber
up rusty/corroded chains (after inspecting care fully) 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:

a. Bent pins or plates.
b. Rusty joints.
c. Peened plate edges.

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

Protruding or Turned Pins: Chains operating with inade­quate lube generate tremendous friction between the pin
and plates (pin and bushing on leaf 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.

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.

Inspect the sheaves, sheave bearings, sheave grooves
and pins for extreme wear, replace as necessary. A worn
sheave can mean several problems, as follows:

a. Chains too tight.
b. Sheave bearings/pin bad.
c. Bent/misaligned chains.

Mast Cable Inspection Procedure

Inspection should be more frequent as cables approach
the end of their useful lives.

Only the surface wires of the cable require inspection, do
not attempt to open the cable. Any deterioration resulting
in any loss of original strength, such as described below,
shall be noted, and then a determination made if further
use would constitute a hazard.

Mast cables must be replaced after machine has been in
service for five (5) years, regardless of cable condition, or
sooner if conditions dictate.

Conditions such as the following shall be sufficient reason
for questioning continual use of the [cable] or increasing
the frequency of inspection:

1. In running ropes, six randomly distributed broken
wires in one lay or three broken wires in one strand
in one lay.

2. One outer wire broken at the point of contact with
the core of the rope which has worked its way out of
the rope structure and protrudes or loops out from
the rope structure. Additional inspection of this sec­tion is required.

3. Wear of one-third the original diameter of outside individual wires.

4. Kinking, crushing, birdcaging or any other damage resulting in distortion of the rope structure.

5. Evidence of any heat damage from any cause.

6. Reductions from nominal diameter of more than;

a. 1/64th in. (0.4mm) for diameters up to and

including 5/16th in. (8mm);

NOTE: A good indicator of a stretched extend/retract cable

is if the adjusting nuts are bottomed out. If no adjust­ment remains the cables have stretched and need
replacemen t.

Also check for cracked, bent, worn, severely corroded, or improperly installed cable ends.

Inspect sheaves, sheave grooves, and sheave pins for excessive wear, replace as necessary.

MAST CABLES ARE TO BE INSPECTED EVERY THREE MONTHS
OR MORE FREQUENTLY AS DESCRIBED FOLLOWING.

WEAR PROTECTIVE GLOVES TO PROTECT HANDS WHEN HAN­DLING CABLE.

3120797 – JLG Lift – 2-3

The periodic inspection shall cover the entire length of the
cable. The inspection frequency shall be based on such
factors as expected cable life as determined by experi­ence on the particular application or similar installations,
severity of environment, percentage of capacity lifts, fre­quency rates of operation, and exposure to shock loads.

2.3 LUBRICATION INFORMATION

Hydraulic System

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.

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

SECTION 2 - SERVICE PROCEDURES

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.

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.

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 of new

machines due to the wear-in of meshing compo­nents.

Hydraulic Oil

For best performance, JLG recommends the use of ISO­Vg grade 32, 46 oil with a viscosity range between 15-250
SUS at 100 degrees F (32-54 cST at 40 degrees C). Refer
to Section 1-5 of this Service Manual for recommended
hydraulic oils.

Changing Hydraulic Oil

Use of any of the recommended hydraulic oils eliminates
the need for changing the oil on a regular basis. 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.

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.

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 1-3 in this Service Manual for an expla­nation of the lubricant key designations appearing in the
Lubrication Chart.

2.4 POSITIONING LIFT FOR ACCESS TO COMPONENTS LOCATED UNDER THE BASE FRAME

Access to the underside of the VP lift can be obtained by
lifting the machine with a fork lift truck, using the fork lift
pockets in the base frame.

Lifting with a Fork Truck (See Figure 2-1.)

1. Choose a fork lift truck capable of safely handling

the full weight of the machine.

2. Locate work area on a firm, level surface.

KEEP MACHINE LEVEL OR SLIGHTLY TILTED TOWARD FORKLIFT
TRUCK WHEN LIFTING TO PREVENT MACHINE FROM SLIDING
OFF LIFTING TINES.

3. When lifting with a fork truck, lift only using the fork

lift-truck pockets running the length of the machine’s
base frame from rear to front.

4. After lifting machine to desired work height, place
support stands under the machine. The support
stands must reach from the floor to the bottom of the
machine and be capable of safely handling the
weight of the machine.

LIFT USING ONLY THE
FORK LIFT POCKETS
RUNNING THE LENGTH
OF THE BASE FRAME

PLACE
SUPPORT
STAND
BETWEEN
MACHINE
AND
FLOOR

Figure 2-1. Accessing Machine Underside

Components by Lifting with a Fork Truck.

2-4 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

2.5 DRIVE MOTOR COMPONENT SERVICE PROCEDURES

Torque Limiting Clutch Maintenance

VP Series machines are equipped with a torque limiting
clutch coupling on each drive axle. The clutch is mounted
inline on the drive axle between the drive wheel and the
drive motor gear box. The clutch is designed to slip at a
pre-set torque if the machines rear wheels are over-driven
while the machine is being towed, pushed or forklifted,
thus preventing damage to the drive gear box. Although
factory pre-set, the clutch assembly and torque should be
checked at the following interval:

• Every 3 months.

Visual Inspection and Limiting Torque Checking Procedure

1. Locate the machine on a firm level surface.

KEEP MACHINE LEVEL OR SLIGHTLY TILTED TOWARD FORKLIFT
TRUCK WHEN LIFTING TO PREVENT MACHINE FROM SLIDING
OFF LIFTING TINES.

2. Carefully raise the lift to gain access to the under­side of the base frame. Refer to Section 2.4, "Posi­tioning Lift For Access to Components Located
Under the Base Frame".

3. Locate the clutch assembly on each rear drive axle and check for the following;

a. Check the coupling chains for any loose or miss-

ing parts, i.e. pins, links, etc., replace if neces­sary.

b. Check that the allen-head set screws on the

(large) clutch adjusting nut are in place and
secure. Tighten or replace if necessary.

c. Check for any debris wedged in or wrapped

around the clutch coupling chains and axle
shafts. Remove debris and clean area if neces­sary.

Checking Clutch - Torque Setting (ft. lb.)

NOTE: Check that the machines brakes are engaged before

applying torque to the rear drive wheels.

1. Remove the drive wheels from the drive axles.

2. Select a torque wrench capable of setting a torque

of at least 185 ft. lb. Insert special tool (P/N-

0080229) into a 3/4" socket on the torque wrench.

3. Slide the tool onto the end of the drive axle aligning
the key on the axle shaft (install key on axle, if nec­essary), with key slot in the tool. (See Figure 2-2.)

4. Turn the torque wrench and note the torque setting
when the torque limiting clutch releases. The torque
(slip) setting should be set at 185 ft. lb. Check both
rear drive axles.

NOTE: The allowable breaking torque for the torque limiting

clutch can be set as much as 35 ft. lb. less than the
factory setting of 185 ft. lb., but never more than the
185 ft. lb. factory setting.

5. If torque setting is OK, re-install the wheels and lower machine, IF NOT, see the following note.

NOTE: If torque setting is outside the allowable range of

specifications, the torque limiting clutch will need
adjustment. See Torque Limiting Clutch Adjustment
following.

SERVICE TOOL

P/N-0080229

(REQUIRES A 1-3/4” SOCKET)

TORQUE

LIMITING

CLUTCH

LOCATION

Figure 2-2. Check Torque Limit Clutch -

Torque Setting.

3120797 – JLG Lift – 2-5

SECTION 2 - SERVICE PROCEDURES

TORQUE LIMIT

CLUTCH

ADJUSTING NUT

ADJUSTING NUT

SET SCREWS

Torque Limiting Clutch Adjustment

NOTE: The large adjusting nut on the side of the clutch

assembly is a standard type thread.
If the torqu e (slip) setting of the clutch assem bly is
under spec (by more than 35 ft. lb.), the large adjust­ing nut must be (tightened) turned clockwise to
increase the torque setting.
If the torque (slip) setting is over spec (over 185 ft.
lb.) the large adjusting nut must be (loosened),
turned counter-clockwis e to dec rea se the torque set­ting.

1. Loosen the two (2) adjusting nut setscrews located
on the large adjusting nut on the clutch assembly.
(See Figure 2-3.)

2. Hold the drive axle steady using service tool (P/N-

0080229) and the torque wrench used to check the
torque setting.

3. Depending on how far off the original torque setting
was (see note at beginning of this procedure),
tighten or loosen the adjusting nut accordingly, then
recheck the (slip) torque setting.

4. When proper torque setting is achieved, re-tighten the two (2) adjusting nut, setscrews.

5. Re-install the drive wheels, remove the jack stand and lower the machine to ground.

Drive Motor Brake Adjustment/Removal

(See Figure 2-4. & Figure 2-5.)
Mounted onto the front of each drive motor housing is a

brake assembly. The brakes are normally ENGAGED
(brakes on) when the machine is parked and are
RELEASED electrically (brakes off) under normal driving
conditions, when the joystick is enabled and pushed in
any direction. The brakes can also be RELEASED manu­ally using the manual brake release lever mounted on the
side of the mast.

NOTE: The brakes are intended only as parking brakes to

keep the machine from moving while at rest. The
brakes are not used to stop the machine during driv­ing operati ons, thi s braki ng is c ontro lled by the dri ve
motors themselv e s . Und er no rmal driving cond itions,
once released the brakes are not engaged again
until the machine comes to a complete stop.

MANUAL

BRAKE

RELEASE

ARM

LIMIT

(MICRO)

SWITCH

MAGNETIC

COIL

HOUSING

MOUNTING

PLATE

ARMATURE

PLATE

FRICTION

BRAKE

DISK

SPRINGS

SHIM WASHERS

Figure 2-3. Torque Limit Clutch -

Adjustment Components.

(AS REQUIRED)

SPACER

Figure 2-4. Brake Assembly Components

2-6 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

FRICTION BRAKE DISK FRICTION BRAKE DISK

ARMATURE PLATE ARMATURE PLATE

MAGNETIC COIL

(Not Energized)

MANUAL

RELEASE ARM/

ADJUSTMENT

SCREW

GAP SETTINGS - BRAKE ON

(Magnet Not Energized)

MOUNTING PLATE MOUNTING PLATE

0.006” GAP
BETWEEN

ARMATURE
PLATE AND

MAGNETIC COIL

0.020” GAP
UNDER

SCREW HEAD

BETWEEN

ARMATURE

PLATE

MAGNETIC COIL

(Energized)

MANUAL

RELEASE ARM/

ADJUSTMENT

SCREW

GAP SETTINGS - BRAKE RELEASED

Figure 2-5. Brake Armature Plate & Brake Disk Adjustment.

Operation (See Figure 2-4. & Figure 2-5.)

When the magnetic coil is not energized (brake on), the
armature plate is pushed away from the magnetic coil sur­face by heavy springs internally mounted in the magnetic
coil housing. This pressure forces the armature plate
against the friction brake disk holding it tight between the
armature plate and the mounting plate. The brake is not
released until either the magnetic coil is energized pulling
the armature plate away from the friction brake disk or the
brake is manually released using the manual brake
release handle.

A correctly adjusted brake will ideally have a measurment
of approximately .006" (but will operate normally at .004" to
.010") between the armature plate and magnetic coil
housing surface when the brakes are ENGAGED (brakes

3. With the brakes ENGAGED measure the air gap
between the armature plate and the magnetic coil
housing. The correct setting should be .006", how­ever the brakes will operate properly if the measure­ment is a minimum of .004" and a maximum of .010".
(See Figure 2-5.)

4. If the air gap falls outside the maximum allowable
setting of .010" the friction disk has worn. To correct
this replace the disk with a new one.

5. It the air gap is below the minimum allowable setting
of .004", recheck the areas between the magnetic
coil housing, armature plate, friction disk and
mounting plate for debris. Clean as neccessary. Also
check that the manual release arm screws are not
tightened to tight.

on).
Never allow any type of lubricant (oil, grease, hydraulic

fluid, etc.) to come in contact with the brake friction disk or

it’s contacting surfaces. Also if the brake becomes
clogged with debris or dirt the brake may not release
properly.

Manual Release Arm - Screw Adjustment

NOTE: Alwa ys c hec k the armature pl ate gap setting is withi n

spec before attem pting to adj ust th e manual release
arm screw adjustment.

1. With the brakes ENGAGED (brakes on) the air gap

Checking/Adjusting Armature Plate Gap Setting

1. First inspect that all parts of the brake assembly are

tight and secure. Tighten as necessary.

2. Inspect the brake for any debris which may be
lodged in the air gap between the armature plate
and magnetic coil when the brakes are ENGAGED
(brakes on); on either side of the friction disk when
the brake is RELEASED (brakes off); or any dirt or
debris lodged between the manual release arm and
the magnetic coil housing. Clean and remove debris
as necessary.

under the head of the manual release arm screw to
the surface of the armature plate should be set at
.020". Adjust using the locknut on the release arm
end of the screw.

2. With the brakes electrically RELEASED (brakes off)
the air gap under the screw head increases to
approximately .026" due to the armature plate move­ment towards the magnetic coil, releasing the fric­tion brake disk. When the brakes are RELEASED
(brakes off) manually the screw head pulls in against
the armature plate releasing the friction brake disk.

0.006” GAP
BETWEEN
FRICTION
DISK AND

ARMATURE

PLATE

0.026” GAP

UNDER

SCREW HEAD

BETWEEN

ARMATURE

PLATE

(Magnet Energized)

3120797 – JLG Lift – 2-7

SECTION 2 - SERVICE PROCEDURES

Brake Assembly Removal

1. Lift the machine to gain access to the underside

(See Section 2-4., "Positioning Lift For Access To
Components Located Under The Base Frame").

2. Disconnect the brake magnetic coil wiring connector
and the brake limit (micro) switch wiring connector
from their wiring harness connectors.

3. Disconnect the manual brake release cable from the
manual brake release arm attached to the brake
assembly.

4. Lower machine back down to ground level.

PLACE MACHINE ON A LEVEL SURFACE BEFORE BEFORE
REMOVING THE BRAKE ASSEMBLIES. MACHINE MAY ROLL
AWAY IF NOT SETTING ON A LEVEL SURFACE.

5. Using the Ground Control Switch, raise the platform
to gain access to the brake assemblies mounted on
the end of the drive motors located at the base of the
mast.

NEVER WORK UNDER AN ELEVATED PLATFORM UNTIL PLAT­FORM HAS BEEN SAFELY RESTRAINED FROM ANY MOVEMENT
BY BLOCKING OR OVERHEAD SLING.

6. Remove the four (4) hex cap screws securing the
brake assembly to the end of the drive motor and
remove the brake assembly from the end of the
drive motor.

6. Reconnect the manual release brake cable to the
manual release lever (Y shaped lever) and adjust
cable so brakes are released when manual release
lever is in the down position. (See Figure 2-6.)

MANUAL

RELEASE

BRAKE
CABLE

SET MANUAL

BRAKE RELEASE

HANDLE TO

FREE WHEELING

AND ADJUST HERE

UNTIL BRAKE DISK

IS COMPLETELY

RELEASED

TO MANUAL

RELEASE

BRAKE

HANDLE

MOUNTED

ON SIDE OF

MAST

BRAKES

ARE RELEASED

WHEN CABLE
PULLS LEVER

IN THIS DIRECTION

Figure 2-6. Manual Release Brake Cable Adjustment.

Brake Assembly Installation

1. Guide the manual release lever, brake coil and brake

limit switch wiring connectors through the opening
in the drive motor cover and base frame while slid­ing the brake assembly onto the front of the drive
motor. Engage the teeth of the disk brake with the
teeth on the drive motor brake gear.

2. If necessary, manually release the brake disk using
the manual release lever to allow the brake assem­bly to turn and align the four holes in the brake
mounting plate with the mating holes in the drive
motor end plate.

3. Secure the brake assembly to the drive motor using
four (4) hex cap screws with washers. Torque evenly
to 44 in. lbs.

4. Lift the machine to gain access to the underside
(See Section 2-4., "Positioning Lift For Access To
Components Located Under The Base Frame").

5. Reconnect the brake coil and brake limit switch wir­ing connectors to their respective wiring harness
connectors.

2-8 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

(2 EACH INSIDE FORK LIFT POCKET)

DRIVE MOTOR MOUNT

DRIVE MOTOR MOUNT

Drive Motor Removal

(See Figure 2-7.)

The VP drive motors consist of three sections, the gear
box atttached to the rear of the drive motor, the electric
drive motor itself, and the brake assembly mounded at the
front of the drive motor. Each drive motor is mounted inde­pendently of the other on a completely removable drive
assembly weldment at the back of the machine.

1. Disconnect the positive battery terminal from the left side battery.

2. Remove the rear plate weldment from the machine,
(plate with the tie down lug) and set aside. Three (3)
bolts hold the top of the rear plate weldment to the
base frame, four (4) bolts attach it to the motor cover
weldment (located under machine) at the back and
on the sides.

3. Carefully raise the lift to gain access to the under­side of the base frame. Refer to Section 2.4, "Posi­tioning Lift For Access to Components Located
Under the Base Frame".

4. Remove the remaining two (2) bolts attaching the motor cover to the base frame and set it aside.

DRIVE MOTOR/

BRAKE WIRING

CONNECTORS

DRIVE MOTOR

ASSEMBLY WELDMENT

5. Disconnect the wiring connectors to the drive motor

and the brake assembly on either or both sides,
depending on which drive assembly(ies) is being
removed.

6. Disconnect the manual release brake cable from the
brake assembly arm on either or both drive motors if
removing the complete drive assembly.

NOTE: If removing each dri ve motor seperately continue to

Step 7. If removing the complete drive assembly
with both motors attached go to Step 11.

7. Remove the one (1) bolt, nut, and two (2) washers
from the front of the drive motor mounting plate.

8. While holding the drive motor in place, remove the
remaining two (2) bolts with washers holding the
drive motor mounting plate to the drive motor
assembly weldment.

9. Slide the drive motor and torque limiting clutch
assembly towards the center of the machine, sliding
the torque limiting clutch off the outer drive shaft.

10. Move drive motor assembly and torque limiting clutch to a suitable work bench for disassembly.

DRIVE MOTOR

ASSEMBLY

WELDMENT

ATTACH BOLTS

MANUAL

RELEASE

BRAKE

CABLE

DRIVE MOTOR

PLATE FASTENERS

(THREE ON EACH MOUNT

ALSO SEE INSET)

COVER

PLATE

REAR PLATE

WELDMENT

Figure 2-7. Drive Motor Assembly Removal.

3120797 – JLG Lift – 2-9

SECTION 2 - SERVICE PROCEDURES

Gear Box Disassembly/Assembly

IF REMOVING THE COMPLETE DRIVE ASSEMBLY, IT WEIGHS
APPROXIMATELY XX LB. AND WILL REQUIRE ASSISTANCE TO
LOWER. PREFERABLY USE A MOVABLE TRANSMISSSION OR
OTHER HYDRAULIC JACK TO CAREFULLY LOWER ASSEMBLY
FROM UNDER MACHINE.

11. Carefully remove the four (4) nuts and washers

(outer most holes on the drive assembly weldment)

from the carriage bolts attaching the drive motor
assembly to the base frame. Be aware of the weight

of the assembly before completely removing the fas­teners, see the CAUTION above.

12. Lower the drive assembly and place on a suitable work surface.

(See Figure 2-8.)

The drive motor gear box is mounted on the rear of each
drive motor transferring power from the electric drive
motor to the rear drive wheels. It is a right angle worm
gear type box with a 50:1 reduction drive ratio. The inter­nal gears and bearings of the gear box are lubricated by

175cc’s of gear oil in an unvented aluminum alloy hous­ing. Early VP machines included a oil drain plug on the
rear surface of the gear box housing, later model
machines do not. The following procedures disassemble
and assemble the gear box housing internal components.

Gear Box Disassembly (See Figure 2-8.)

1. Remove the drive motor/gear box/brake assembly

from the machine using the procedure outlined pre­viously in this section of the manual.

Figure 2-8. Drive Motor Gear Box Assembly.

2-10 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

NOTE: The gear oil can be drained out when the side cover

is removed in th e next step. Remove the side cover
from the gear box with the drive shaft si de pointing
down, then tilt drive motor/gear box assembly to
drain the oi l into a suit able container.

2. Remove the four (4) hex cap screws securing the
side cover to the gear box housing, and remove the
side cover and rubber seal ring. (Note: Early model

machines did not have the rubber seal ring and were
sealed with sealant only.) Be careful not to scratch or

gouge the mating surfaces between the cover and
the gear box housing. This area is sealed by the rub­ber ring/sealant and may leak oil if damaged.

3. Remove the wave washers from atop the large and
small bearings and lay inside their respective holes
in the side cover.

4. Using a suitable catch container, drain the gear oil from the gear box housing.

5. Remove the drive shaft assembly from the housing.
Place the drive motor/gear box assembly on a
hydraulic press with the open side of the gear box
housing facing down. Support the gear box housing
surface but do not block the free travel of the drive
gear and bearings, on the drive shaft or the pinion
gear assembly.

6. With the open surface of the housing properly sup­ported, carefully press the drive shaft down through
until it is free of the housing. When the drive shaft
assembly is free, slide it completely out of the hous­ing.

7. To remove the large (47mm) (cover side) bearing
and (housing side) bearing from the drive shaft, use
a suitable hydraulic press and press the bearing(s)
off the shaft. Keep the spacer from between the
cover side bearing and the drive shaft gear for reuse
during assembly.

8. To remove the small (32mm) bearing(s) from the
gear (brass) and pinion assembly, use a suitable
hydrauic press and press the bearing(s) off the gear
and pinion shaft.

9. To remove the (brass) worm gear from the pinion
assembly, use a suitable hydraulic press and press
the gear off the pinion shaft. Keep the (brass) gear
key for reuse during assembly.

10. Inspect the drive shaft seal for cuts, cracks and
wear, or if showing signs of leakage. Replace if nec­essary.

Gear/Pinion Shaft Assembly (See Figure 2-9.)

1. Locate the pinion gear/shaft, place the key for the

(brass) worm gear into the slot on the gear shaft.

2. Press the (brass) worm gear onto the pinion shaft
and align the keyway in the (brass) worm gear with
the key on the pinion shaft. Press the (brass) worm
gear onto the shaft until it bottoms out against the
pinion gear teeth.

NOTE: Press bearings onto the shaft pressing only against

the bearing inner race. Do not press against the
outer race or damage could occur to the bearing.

3. Press the small (32mm) bearings onto the ends of
the pinion shaft. The inner race of the bearing on the
pinion gear side can be bottomed out against the
pinion gear. Do not press the bearing on the (brass)
worm gear side of the shaft in tight against the
(brass) worm gear. This bearing must be flush with
the end of the shaft on the outside, yet have clear­ance from the (brass) worm gear on the inside, so it
can rotate freely.

Drive Shaft Assembly (See Figure 2-10.)

1. Slide the (housing side), 42mm x 25mm x 12mm

(thinner) bearing onto the long end of the drive shaft.
Press the bearing inner race until it bottoms against
the shaft shoulder between the drive gear and the
bearing.

2. Slide the narrow spacer onto the drive gear end of
the shaft and press the (cover side) 42mm x 20mm x
14mm (wider) bearing onto the drive shaft until it
bottoms against the spacer. This bearing should be
flush with the end of the drive shaft.

SIDE PROFILE

32mm

BEARING

WORM

GEAR

(BRASS)

PINION GEAR/

SHAFT

LEAVE

GAP HERE

32mm

BEARING

WORM GEAR

KEY

Figure 2-9. Gear/Pinion Shaft Assembly.

3120797 – JLG Lift – 2-11

SECTION 2 - SERVICE PROCEDURES

Final Gear Box Assembly

1. If necessary, install a new drive shaft lip seal into the

drive shaft hole in the gear box housing before
assembling the drive shaft gear set into the gear
box. Install the seal so it is even with the bottom of
the chamfer in the drive shaft hole on the outside of
the housing and flush with the bearing seat on the
inside of the housing.

2. Lube the drive shaft seal with a thin film of oil before sliding the drive shaft over the seal.

3. Position the gear box with open cover side up, allow
space under the gear box for the drive shaft to
extend through without obstruction.

4. Hold the gear and pinion, and drive shaft assembies
together with the pinion gear and the ring gear on
the drive shaft meshing. Now carefully slide these
assemblies into the gear box housing sliding the
drive shaft through the drive shaft lip seal.

NOTE: While assembling the gear assemblies into the gear

box housing, be careful with the drive shaft seal and
the softer brass worm gear and brass drive worm
gear from the drive motor.

5. Continue to drop the gear assemblies into the gear
box, align the bearings with the bearing seats in the
housing on both assemblies. Drop the gear and pin­ion (smaller) bearing into it’s seat first, while wiggling

that gear set align the drive shaft bearing and wiggle
it into it’s seat. When both are seated continue to
next step.

6. With the gear box still positoned with the open cover
side up, fill the gear box with six (6) ounces (U.S.)
(175cc’s) of good quality worm gear oil (Specifica-
tion - SAE 90 weight - AGMA#5 - EP Compounded).
When pouring the gear oil, wet the gears and bear­ings with the oil.

7. Wet with gear oil and place the large wave washer
on the end of the drive shaft bearing and the small
wave washer on the end of the gear and pinion bear­ing.

8. Clean the mating surfaces of the side cover and the
gear box and check that the cover dow guide pins
are properly installed in the cover.

9. On older model gear boxes apply sealant to the
cover mating surface on the gear box. On newer
model gear boxes insert the rubber seal into the
groove in the cover.

10. Using the cover dow guide pins, place the cover onto the gear box housing.

11. Secure using the four (4) hex cap screws, torque screws evenly to 90 in. lbs.

12. Install the drive motor back onto the machine.

PINION

GEAR

SPACER

PINION GEAR KEY

42mm x 25mm x 12mm

BEARING

DRIVE SHAFT

SIDE PROFILE

42mm x 20mm x 14mm

BEARING

Figure 2-10. Drive Shaft Assembly.

2-12 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

SPRING BRACKET

Drive Motor Brush Replacement

Each drive motor contains two (2) brushes, the brushes
are located under the two (2) large round slotted brush
caps on the front end of each drive motor.

BRUSH CAP

DRIVE MOTOR

BRUSH

ASSEMBLIES

LOCATED

INSIDE

HERE

BRUSH CAP

BRAKE

ASSEMBLY

Figure 2-11. Drive Motor Brush Location.

Brush Removal (See Figure 2-12.)

Removal of the brushes also requires the removal of the
drive motor(s) from the machine, see procedure
described earlier in this section for instructions to remove
the drive motors. If not already done, disconnect the posi­tive (+) battery cable from the left side battery before pro­ceding.

1. Unscrew the large round brush caps from each side
of the drive motor, use as large a screw driver as
possible.

2. The brushes are retained by constant-force, roll-type
springs. To remove the springs, press inward on the
end of the spring retaining bracket using the tip of a
pair of long nose pliers or other appropriate tool.
The brushes should pop out, if not, they can be
removed by pulling outward on the spring brackets
with a pair of long nose pliers after the inside ends
are unhooked.

3. Now pull the brush out of the brush box by it’s wire (pig-tail).

NOTE: If only inspecting the brushes, it is not necessary to

remove the pig-tail terminal from it’s connection to
the brush box.

4. Loosen the the screw securing the pig-tail terminal
end to the brush box and slide the terminal end out
from under the screw completely removing the
brush from the drive motor.

DISCONNECT THE POWER LEADS FROM THE POWER SOURCE
BEFORE INSPECTING OR REPLACING BRUSHES.

Brush Cleaning and Inspection

Brush wear rate varies depending on the individual appli-

cation’s duty cycle, and should be inspected at frequent
intervals to determine an appropriate inspection schedule.
Brushes should be replaced before they are less than .375
in. (9.5mm) in length. Carbon dust accumulation should
be removed periodically. If the end shield has been
removed from the drive, a clean, dry, non-linting cloth can
be used for cleaning. DO NOT use solvents as they my
damage non-metallic parts and adversely affect subse­quent brush commutation.

SPRING BRACKET

SPRING

BRACKET

HOOKS

BRUSH

PIGTAIL WIRE

Figure 2-12. Drive Motor Brush Installation.

BRUSH BOX

BRUSH BOX

INSULATOR

3120797 – JLG Lift – 2-13

SECTION 2 - SERVICE PROCEDURES

Brush Reassembly (See Figure 2-12.)

MAKE CERTAIN THAT THE GROUND WIRE IS SECURELY RECON­NECTED TO THE GROUND TERMINAL IF REMOVED. LEADS,
INTERNAL TO THE SHEILD, MUST BE ROUTED AWAY FROM THE
ARMATURE, (E.G.: BE CLOSE TO THE INSIDE WALL OF THE
ALUMINUM SHIELD) TO PREVENT A SAFETY HAZARD AND/OR
DAMAGE TO THE MOTOR.

CORRECT

1. Install the brush (pig-tail) terminal end under the

screw on the brush box in the same manner as the
old brush that was removed and tighten the screw.

2. Slide the body of the brush into the brush box, be
certain that the wire (pig-tail) is aligned with the slot
in the base of the brush box so that it can "feed" into
the brush box slot as the brush wears down.

NOTE: The pig-tail wire should be formed to rest against the

nonmetallic insulator. It must be spaced from any
metallic surfaces other than the brush box by a mini­mum of .125 in. (3mm).

3. Now install the brush retaining spring bracket. Grasp
the tip of the spring bracket such that the roll-type
spring will be on the "brush side" of the brush box,
and resting on top of the brush when the brush
spring is completely installed.

4. Push the spring bracket slowly into it’s slot while let­ting it’s two attaching hooks slide on the wall of the
brush box.

5. Stop, but do not release the spring bracket when it’s
hooks slip around the edge of the brush box.

6. While still grasping the spring bracket with the pliers,
slowly bring the spring back out of the brush box
until the hooks latch around the edge of the brush
box.

7. Now release the spring bracket and check that it is
lying flat against the brush box wall. If it is "cocked" it
is improperly seated and will have to be reinstalled.

INCORRECT

Figure 2-13. Correct/Incorrect Brush Spring Bracket

Positions.

IMPORTANT

THE SPRING BRACKET MUST BE ALSO LIE COMPLETELY INSIDE
THE BRUSH BOX AND NOT OUT OVER THE EDGE. THE ROLL
END OF THE SPRING MUST BE CENTERED ON THE TOP OF THE
BRUSH. (SEE FIGURE 2-13.)

8. Also apply slight pressure by pulling up on the
spring bracket to be certain it is hooked securely
around the brush box wall at the bottom of the brush
box.

9. Screw the brush caps back into the end shield using the largest possible screwdriver.

10. Reinstall the drive motor(s) to the machine and reconnect the power source.

IMPORTANT

NEW BRUSHES MAY BE SEATED BY RUNNING THE DRIVE
MOTOR AT NO LOAD. PROPER SEATING IS REQUIRED FOR
LOWEST BRUSH NOISE LEVEL.

2-14 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

2.6 PLATFORM CONTROL BOX SERVICE PROCEDURES

Joystick Calibration Procedure

1. Turn off all power to the platform control.

2. Move the joystick to the maximum forward position

and hold it there.

NOTE: Joystick will be held in the maximum forward position

until asked to release it in Step 5.

JOYSTICK ASSEMBLY

S/N- 02996 TO PRESENT

(INCLUDES DRIVE ENABLE BUTTON)

TOUCH PAD

UPPER

HOUSING

INTREGRATED

CIRCUIT

BOARD

SWITCH

3. Turn on power to the platform control, nine (9) LED’s

will flash rapidly on the platform control touch pad.

4. Depress the horn switch pad, the alarm will sound
for about one (1) second, then release the horn pad.

5. Now release the joystick to the neutral position.

6. Turn off system power.

The joystick calibration is now complete.

JOYSTICK

ASSEMBLY

PRIOR TO

S/N- 02996

(USED THE

TOUCH PAD

ENABLE

SWITCH)

LOWE R

HOUSING

SPEED

CONTROL

KNOB

EMERGENCY

STOP SWITCH

BUTTON

SPEED

CONTROL

SWITCH

EMERGENCY

STOP SWITCH

Figure 2-14. Platform Control Box Assembly (Exploded View)

3120797 – JLG Lift – 2-15

SECTION 2 - SERVICE PROCEDURES

IMPORTANT

IMPORTANT

Platform Control Box Disassembly

DO NOT ATTEMPT TO DISASSEMBLE THE PLATFORM CONTROL
BOX IF MACHINE IS STILL UNDER WARRANTY. OPENING THE
PLATFORM CONTROL BOX WHILE THE MACHINE IS UNDER
WARRANTY WILL VOID THE WARRANTY. IF UNDER WARRANTY
REQUEST A REPLACEMENT BOX FROM THE FACTORY.

The VP Series platform control box allows for replacement
of five (5) components internal to the box.

• Controller Integrated Circuit Board

• Joystick Assembly

• Emergency Stop Switch

• Speed Control Switch

• Touch Pad Switch Assembly

Except for the touch pad switch assembly, which plugs
into the circuit board, replacement of each component
requires unsoldering, then soldering each replacement
components’ wiring to the controller’s integrated circuit
board. Due to the small contact area when connecting
each wire to the circuit board this soldering requires pre­cise temperatures and neatness of the soldered point
itself so as not to destroy the circuit board or cross any of
the circuit paths on the board.

Lower Half Of Housing Removal

1. Position the control box upside down and remove

the six (6) screws attaching the lower half of the
housing to the upper half of the control box housing.

2. Lay screws and lower housing aside.

Joystick Assembly Removal

NOTE: To completely remove the joystick assembly, its wir-

ing will need to be unsoldered from the intregrated
circuit board.

ELECTROSTATIC DISCHARGE CAN DAMAGE COMPONENTS ON
THE INTEGRATED CIRCUIT BOARD. PLACE THE PLATFORM
CONTROL BOX ON A NON-CONDUCTIVE SURFACE WHEN OPEN­ING THE BOX AND WORKING DIRECTLY WITH THE CIRCUIT
BOARD.

Removing Control Box From Platform

1. Turn off all power to the platfom control box.

2. Unhook the wiring harness cable at the quick-dis-

connect coupling. (Early VP models were not
equipped with the quick-disconnect coupling, skip to
Step 4.)

3. Remove the platform control box and box mount to a suitable work surface.

4. Remove the control box from the control box mount
by removing the four (4) nuts from the studs on the
bottom of the control box.

5. Unplug the wiring harness cable connector on the back of the lower housing half.

6. Lay control box mount and wiring harness assembly aside.

1. Remove the four (4) screws from the top of the bezel
around the base of the joystick and slide the joystick
assembly out of the upper housing.

2. Unplug the touchpad switch ribbon connector from the circuit board connector socket.

2-16 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

3. Remove the four (4) screws attaching the circuit board to the upper housing.

NOTE: If reusing the circuit board be careful when unsolder-

ing component wires DO NOT OVERHEAT BOARD.

4. Position the circuit board and unsolder the wires
from the joystick assembly at the J2, J3 and J7 loca­tions on the circuit board. (See Figure 2-15.)

NOTE: (VP model joystick assemblies prior to S/N- 02996

did not have the d rive enable button on the joystick
knob. Wires from this design were attached in the J3
location on the circuit board only.)

5. With all the joystick wiring unsoldered remove joy­stick assembly from the control box.

Emergency Stop Switch Removal

1. Remove the switch part of the emergency stop

switch by carefully prying upward at the corner of
the switch using a straight blade screwdriver. This
will seperate the switch from the reset button part of
the emergency stop button assembly.

2. Position the circuit board and locate the emergency
stop switch wires connected at locations J8, J9, J10
and J11. Unsolder the four (4) wires to the switch to
remove the switch from the board. (See Figure 2-15.)

J2 - J7

JOYSTICK

WIRING

(2 WIRES)

(Later Models With

Enable Button On

Knob Only)

J8 - J9

J10 - J11

EMERGENCY

STOP

SWITCH

(4 WIRES)

TOUCHPAD

SWITCH

CONNECTOR

SOCKET

Figure 2-15. Platform Control - Circuit Board Component Wiring Connections.

J3

JOYSTICK

WIRING

(5 WIRES)

J5

SPEED

CONTROL

SWITCH

(3 WIRES)

3120797 – JLG Lift – 2-17

SECTION 2 - SERVICE PROCEDURES

WIRES FROM JOYSTICK

3. Remove the reset button part of the emergency stop

switch by unscrewing the collar on the inside end of
the reset button assembly.

Speed Control Switch Removal

1. Remove the speed control knob by pulling up on the

knob until it is free of the switch shaft.

2. Loosen and remove the retaining nut and lock
washer from the switch collar and pull the switch out
of the housing.

Touch Pad Switch Removal

1. Unplug the touch pad ribbon cable connector from

the circuit board connector socket. (See Figure 2-

15.)

2. Using a thin tool, start by lifting an edge of the touch
pad switch and slowly peel away it from the face of
the upper housing until completely free.

Platform Control Box Assembly

To assemble the components back into the control box
follow the previously outlined disassembly procedure and
reverse the steps for the component being installed. The
following are additional guidelines for assembling each
component.

NOTE: Be careful when soldering component wires to the

circuit board DO NOT OVERHEAT BOARD.

Joystick Installation

1. Use the following illustrations to reattach the wires

from the joystick to the circuit board.

3. Position the circuit board and locate the speed con­trol switch wires connected at location J5. (See Fig-
ure 2-15.) Unsolder the three (3) wires to the switch
to remove the switch from the platform box.

CIRCUIT BOARD

COMPONENT SIDE

YELLOW
BLUE
BLACK
RED
WHITE

J3

CONTROL

2-18 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

ORANGE

WHITE W/ORG

CIRCUIT BOARD

COMPONENT SIDE

WIRES FROM SPEED

Speed Control Switch Installation

1. Use the following illustrations to reattach the wires

from the speed control switch to the circuit board.

WIRES

WHITE (light gauge)

FROM
JOYSTICK
CONTROL

(Later Model

Joystick

w/Drive

Enable

on Knob)

2. If damaged replace the gasket between upper hous­ing surface and the joystick mounting surface before
assembling.

YELLOW (light guage)

CIRCUIT BOARD

COMPONENT SIDE

Emergency Stop Switch Installation

1. Use the following illustration to reattach the wires

from the emergency stop switch to the circuit board.

GREEN

J5

CONTROL SWITCH

Touch Pad Switch Installation

1. Thoroughly clean the surface of the upper housing

where the touch pad switch adheres to the upper
housing.

2. Remove all traces of silicone sealant from around
the slot where the ribbon cable connector passes
through the housing.

CIRCUIT

BOARD

COMPONENT

SIDE

2. If damaged replace the gasket between the stop

switch base plate and the upper housing mounting
surface.

RED (PIN 21)
BLACK (PIN 13)
BLACK (PIN 14)
RED (PIN 22)

WIRES FROM

EMERGENCY

STOP SWITCH

APPLY SILICONE

SEALANT HERE

IN THIS SLOT

3. Remove the adhesive backing off the new touch pad

switch, keep this surface clean and free of debris
during assembly.

4. Assemble the new touch pad switch to the upper
housing surface by first sliding the ribbon cable con-

3120797 – JLG Lift – 2-19

SECTION 2 - SERVICE PROCEDURES

nector from the touch pad switch through the slot at
the top of the housing. Before pressing the touch
pad adhesive side to the upper housing mounting
surface, visually align the touch pad edges with the
edges of the recess in the housing mounting sur­face.

5. Once the touch pad is installed, on the underside of
the housing apply just enough silicone sealant to fill
the small slot around the ribbon cable to help seal
the slot and also strengthen the ribbon cable con­nection at the touch pad surface.

6. Re-install the circuit board and plug the ribbon cable
connector into the circuit board cable socket.

Lower Half Housing Installation

1. Before installing the lower half housing apply a non-

conductive grease to the square holes of the wiring
harness connector socket on the inside of the hous­ing socket. This will help keep out dirt and moisture.

WIRING HARNESS

CONNECTOR SOCKET

2.7 BATTERY CHARGER ASSEMBLY AND DISASSEMBLY

General Information

IMPORTANT

DO NOT ATTEMPT TO DISASSEMBLE THE BATTERY CHARGER
IF MACHINE IS STILL UNDER WARRANTY. OPENING THE BAT­TERY CHARGER WHILE THE MACHINE IS UNDER WARRANTY
WILL VOID THE CHARGER WARRANTY. IF UNDER WARRANTY
REQUEST A REPLACEMENT CHARGER FROM THE FACTORY.

ALSO BEFORE REPLACING ANY COMPONENT, USE THE
CHARGER MANUFACTURERS TROUBLESHOOTING GUIDE
INCLUDED WITH THE MACHINE FOR CHECKING THE INTERNAL
AC AND DC CIRCUITS TO DETERMINE WHICH COMPONENT HAS
FAILED. COMPLETE WIRING DIAGRAMS PERTAINING TO YOUR
MODEL CHARGER ARE ALSO INCLUDED IN THE MANUFACTUR­ERS CHARGER MANUAL.

The VP Series battery charger allows for replacement of
the following internal components. Consult your Illustrated
Parts Manual for part numbers of these components
which are available from the JLG Parts Department:

• Transformer

• Printed Circuit Board

2. Carefully slide the lower housing onto the upper half
of the platform control box assembly until seated
completely against the upper housing edges.

3. Secure lower half housing to the upper half housing
using the six (6) screws removed during dissassem­bly.

• Shunt Assembly

• Interlock Relay

• SCR Rectifier

• AC Circuit Breaker

• DC Circuit Breaker

Replacement and troubleshooting of these components
requires removal of the battery charger from it’s mounting
position on the machine.

Battery Charger Removal

1. Remove the rear cover from the machine.

2. Unbolt and lower the MC-1 Controller Box.

3. Remove the four (4) capscrews securing the charger

to it’s mounting plate.

4. Disconnect the DC wiring from the positive/negative
battery terminals and interlock connector from the
wiring harness.

5. Remove the charger from the machine.

2-20 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

Battery Charger Part Replacement

Cover Removal

1. Remove the eight (8) screws on the sides of the

charger cover and remove cover.

Transformer Replacement

1. Disconnect the wiring connecting the the trans-

former to other components within the charger
assembly.

2. Remove the four nuts from the cap screws securing
the transfromer brackets to the base of the charger
chassis.

3. Remove transformer.

Printed Circuit Board Replacement

1. Disconnect the wide wiring connector from the end

of the circuit board.

2. Remove the four (4) screw attaching the card to the front face of the charger chassis.

3. Remove the circuit board.

Shunt Assembly Replacement

1. Carefully remove the screw from each end of the

shunt assembly. The white insulator may need to be
restrained to keep it from turning while removing the
shunt assembly fasteners. Also make note of the
position of each washer, nut and wire connector
when removing for later assembly.

3120797 – JLG Lift – 2-21

SECTION 2 - SERVICE PROCEDURES

Interlock Relay Replacement

1. Disconnect the wiring connected to the relay.

2. Remove the two (2) nuts securing the interlock relay

to the chassis base.

3. Remove the relay.

SCR Rectifier Replacement (Either Side)

1. Remove the wiring from the SCR Rectifier.

2. Remove the nut securing the rectifier to the insulated

aluminum chassis bracket.

3. Remove the SCR Rectifier.

AC Circuit Breaker Replacement

1. Disconnect wiring connected to the breaker poles.

2. Remove the two (2) nuts securing the AC breaker to

the chassis screws.

3. Remove the breaker from the chassis.

DC Circuit Breaker Replacement

1. Remove the wiring from the DC breaker terminals.

2. To remove the breaker from the front face of the

charger, on the inside of the charger front face, push
in on the tabs located on the sides of the breaker
assembly and remove the breaker out the front of
the charger.

LOCKING

TABS

2-22 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

2.8 MAST ASSEMBLY AND DISASSEMBLY PROCEDURES

The VPSP personnel lift mast sections are contructed of
extruded aluminum, protected with an anodized surface
finish. The mast sections are interlocked into each other
when assembled, by internally mounted slide pads at the
top and bottom of each mast section. These slide pads
run up and down in slide pad channels on each side of
the mast.

The VPSP model mast assembly contains a different num­ber of mast sections as shown following;

Table 2-2. VPSP Mast Component Features

Model

No. of Mast

Sections

15VPSP 5 Chain

Assembly procedures for all mast sections is basically the
same, carefully slide the mast sections together from bot­tom until mast ends are even. (When sliding the mast sec-

tions together, be careful not to scratch the anodized
surface). Assemble the hardware to the bottom of mast

section first, slide this section out the top of previous sec­tion and assemble hardware to the top of mast, (See Fig-
ure 2-1.). Always install slide pad shims with slide pads

Extend/Retract

Device

inserted into the slide pad channels, (ends of mast sec­tions even). Applying silicone spray onto the slide pads

and slide pad channels before assembly will help mast
sections slide easier after slide pads have been properly
shimmed.

Mast Disassembly Procedure

1. After the mast assembly has been removed from the

machine, lay the mast assembly down on a suitable
work table with the platform mounting section on
top, facing up.

2. Remove the sequencing cables and hardware from
the sides of the mast assembly. Also remove the
covers from the top of the mast assembly.

MAST SECTION-5 - REMOVAL

3. Remove chain adjust nuts from threaded ends of

chain attached to the chain anchor plate (lower) on
BOTTOM end of mast section-5 (platform mounting
section). Push threaded ends of chain through
anchor plate.

4. At the TOP of mast section-5, pull chains out and
allow to hang loose. (Be certain floor surface is

clean and free of any metal chips or debris which
may stick to lubricated chains)

OPEN RAIL

(REFERS TO OPEN RAIL

FRONT OF MAST SECTION)

CLOSED RAIL

(REFERS TO CLOSED RAIL

BACK OF MAST SECTION)

TOP

(REFERS TO TOP END

OF MAST SECTION

WHERE COVER AND

SHEAVE WHEELS

ARE ATTACHED)

BOTTOM

(REFERS TO BOTTOM END OF

MAST SECTION WHICH SETS IN

MACHINE’S BASE FRAME)

Figure 2-16. Mast Section - Assembly Reference.

3120797 – JLG Lift – 2-23

SECTION 2 - SERVICE PROCEDURES

NOTE: When sliding mast sections apart, be careful not to

scratch or score the anodized surface in the slide
pad channels.

5. Carefully slide mast section-5 out the BOTTOM of
mast section-4 rails. Disassemble slide pads, shims
and chain anchor plate from mast section-5, if nec­essary.

MAST SECTION-4 - REMOVAL

6. Remove chain adjust nuts from threaded ends of

chains attached to the chain anchor plate (lower) on
BOTTOM end of mast section-4. Push threaded
ends of chains through anchor plate.

7. At TOP of mast section-4, pull chains out and allow
to hang loose. (Be certain floor surface is clean and

free of any metal chips or debris which may stick to
lubricated chains)

8. Slide mast section-4 out the TOP of mast section-3
far enough to allow access to the chain sheave
wheel assembly.

9. Remove countersunk-flathead screws securing
chain sheave wheel assembly attach bars on both
side rails at TOP of mast section-4 and remove
sheave wheel assembly.

NOTE: When sliding mast sections apart, be careful not to

scratch or score the anodized finish in the slide pad
channels.

10. Carefully slide mast section-4 out BOTTOM of sec­tion-3. Remove slide pads, shims and cable anchor
plate, if necessary.

MAST SECTION-3 - REMOVAL

11. Remove chain adjust nuts from threaded ends of

chain attached to the chain anchor plate on BOT­TOM end of mast section-3. Push threaded ends of
chain through the anchor plate.

12. At TOP of mast section-3, pull chains out and allow
to hang loose, (be certain floor surface is clean and

free of any metal chips or debris which may stick to
lubricated chains).

13. Slide mast section-3 out TOP of mast section-2 far
enough to allow access to the chain sheave wheel
assembly.

14. Remove countersunk-flathead screws securing
chain sheave wheel assembly attach bars on both
side rails at TOP of mast section-3 and remove the
sheave wheel assembly.

15. While mast section-3 is still extended from section-2
remove the pin attaching the chain anchor plate to
the TOP of mast section-3. Remove chains.

16. Carefully slide mast section-3 out BOTTOM of sec­tion-2. Remove slide pads, and shims, if necessary.

MAST SECTION-2 - REMOVAL

17. Slide mast section-2 out TOP of mast section-1 far

enough to allow access to the chain assembly
anchor block/sheave wheel assembly.

18. Remove countersunk-flathead screws securing
chain anchor block/sheave wheel assembly attach
bars on both side rails at TOP of mast section-2.

19. Slide the chain anchor block/sheave wheel assem­bly and hydraulic cylinder out the TOP of mast sec­tion-2 far enough to allow removal of the sheave
wheel attach bars, sheave wheels and sheave pin
from chain assembly anchor block.

20. Remove the setscrew holding the hydraulic cylinder
rod onto the chain assembly anchor block. Lay
chain assembly/anchor block to side.

21. Remove the hydraulic cylinder through BOTTOM of
mast section-2, be careful not to nick or score cylin­der rod surface while removing.

NOTE: When sliding mast sections apart, be careful not to

scratch or score the anodized finish in the slide pad
channels.

22. Carefully slide mast section-2 out BOTTOM of sec­tion-1. Remove slide pads and shims, if necessary.

MAST SECTION-1 - DISASSEMBLY

23. Slide the TOP of remaining mast section-1 out over

edge of work surface and remove the pins attaching
the chain anchor block to mast section-1. Remove
chain/anchor block assemblies from mast and lay
aside.

24. Remove slide pads and shims from mast section-1.

Mast disassembly should now be complete.

NOTE: When sliding mast sections apart, be careful not to

scratch or score the anodized finish in the slide pad
channels.

2-24 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

Mast Assembly

(See Figure 2-2.)

MAST SECTION 1 - ASSEMBLY

1. Place mast section-1, rail (open) side up (See Figure

2-1.) on a clean, flat surface (preferably a table or
work bench capable of supporting the weight of the
entire mast assembly). Slide mast out over end of

work surface far enough to allow access to the chain
anchor attach hole near the top of the mast.

2. Locate the two (2) single (wide) chain assemblies
and attach to the large triangular shaped anchor
plate (if not already attached). Lay out the chain/
anchor plate assembly with the anchor plate end
towards top of the mast. (Be certain floor surface is

clean and free of any metal chips or debris which
may stick to lubricated chains).

3. Insert the anchor plate/chain assembly end into the
top of mast section-1 and secure using the large
anchor plate attach pin, spacer, and pin keeper.

MAST SECTION 2 - ASSEMBLY

NOTE: When sliding mast sections together, be careful not

to scratch or score the anodized finish in the slide
pad channels.

4. Locate mast section-2, carefully slide mast section-2
closed rail into section-1 open rail. Slide sections
together until ends are even.

5. Insert slide pads into the slide pad channels at bot­tom end of mast between section-1 and -2, (one on
each side of the mast), with beveled surface facing
out towards section-1.

6. Thread slide pad attaching bolts, (two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt), through holes in
mast section-2 inside rail, into the slide pad inserts.
Thread in enough to hold pad in place.

7. Shim slide pads using the following steps:

NOTE: Always use the an even amount of shim material

behind slide pads on both sides of the mast rails.
This will keep mast sections centered in rail chan­nels and prevent any distortion of the mast section.

a. Start with a .036" thick shim and a .075" thick

shim per side at each slide pad.

b. Slide shims into place between slide pad and

mast rail. Tighten the slide pad mounting bolts,
be sure there are no air gaps between shims,
shim and mast or shim and slide pad when tight­ened.

c. Check mast section for side play. If play exists

add .015" shims dividing the thickness equally

between both sides of mast. Insert shims until
the shims cannot be inserted halfway by hand
with the mast pulled to the opposite side.

d. When mast slide pads are shimmed properly,

there should be no side to side movement of
slide pad in rail channel. Mast sections should
be snug in channels but still be able to slide in
channel by hand.

8. Insert slide pads into the slide pad channels (top of
mast) between section-1 and -2, (one on each side
of the mast), with beveled surface facing in towards

section-2.

NOTE: Before fastening and shimming the slide pad on the

top left side of the mast, install a sequence cable
bracket against the mast under the flatwasher.

9. Thread slide pad attaching bolts, two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes in
mast section-1 outside rail (top of mast) and into the
slide pad inserts. Thread in enough to hold pad in
place.

10. Shim per instructions in step 7, Mast Section 2 ­Assembly.

NOTE: If hydraulic cylinder needs to be extended, the pro-

tective caps on the extend and return ports will need
to be temporarily removed. Be careful not to nick or
scour rod surface when extending, also catch any oil
draining out of cylinder to avoid spillage onto work
area.

11. Slide mast section-2 out of mast section-1 approxi­mately one foot.

12. Locate the hydraulic lift cylinder, slide the lift cylinder
into the closed rail side of mast section-2 with rod
end to top and port end to bottom of mast. Cylinder
should extend out of mast on both ends. Return
tube should be on right side when facing bottom of
mast assembly.

13. Assemble one of the narrow chains sets (#444) and
to the small chain anchor plate using the pins, wash­ers and cotter keys. Set aside.

14. Locate the chain anchor block and slide it onto the hydraulic cylinder rod end.

15. Lay out the chain(#444)/anchor plate assembly with
anchor plate end towards mast, (be certain floor sur-

face is clean and free of any metal chip or debris
which may stick to lubricated chains or lay chains in
a clean bucket).

16. Assemble the chain/anchor plate assembly and the
chain anchor block to the cylinder rod end using the
anchor plate/block attach pin and snap ring.

3120797 – JLG Lift – 2-25

SECTION 2 - SERVICE PROCEDURES

MAST TOP COVER

(TOP OF HYD. CYL.)

CHAIN ANCHOR PLATE

SHEAVE WHEEL

SECTION-4

SHEAVE WHEEL

ASSY.

SECTION-4

MAST

SECTION-5

SECTION-3

ASSY.

MAST

CHAIN ANCHOR

PLATE

(UPPER)

CHAIN SET

SECTION-2

SHEAVE WHEEL

ASSY.

CHAIN

SET

CHAIN SET

CHAIN ANCHOR

PLATE

(UPPER)

ANCHOR PLATE

ATTACH PIN

ATTACH

PIN

KEEPER

SEQUENCE

CABLE

ATTACH AS SY.

(UPPER)

CHAIN

ANCHOR BLOCK

CHAIN ANCHOR

PLATE

SLIDE

PAD

MAST

SECTION-2

MAST

SECTION-3

SLIDE

PAD

(LOWER)

Figure 2-17. 15VPSP Mast Assembly.

HYDRAULIC LIFT

CYLINDER

CYLINDER MOUNT

PLATE

MAST

SECTION-1

CYLINDER MOUNT

SEQUENCE

CABLE

ATTA CH AS SY.

(LOWER)

2-26 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

Figure 2-18. Mast Chain Routing Diagram.

3120797 – JLG Lift – 2-27

SECTION 2 - SERVICE PROCEDURES

17. Assemble chain sheaves on chain assembly anchor
block (attached to cylinder rod end) and attach to
mast section-2 using following steps;

a. Insert sheave pin through anchor block and cyl-

inder rod on cylinder rod end.

b. Load three 1" flatwashers onto the sheave pin on

each side of the anchor block.

c. Place sheave wheels (for wide #544 chain) on

sheave pin, one each side of anchor block.

d. On the outside of each sheave wheel, place

another 1" flatwasher, a roll pin (into the slot in
each end of the pin), and then place a sheave
pin support bar (rectangular plate with threaded
holes on each side of pin bore hole).

e. Slide the whole anchor block/cylinder assembly

with sheave pin, wheels and pin support bars
into top of mast section-2.

f. Align the threaded holes in the attach bars on

each side of the mast and attach to top of mast
section-2 using two (2) 3/8"-16UNC x 1/2" long
socket head-countersunk-flathead cap screws
each side. Coat threads with Loctite #171 and
tighten.

18. Slide mast section-2 back into section-1 until ends are even.

MAST SECTION 3 - ASSEMBLY

NOTE: When sliding mast sections together, be careful not

to scratch or score the anodized finish in the slide
pad channels.

19. Carefully slide mast section-3 into section-2 until ends are even.

20. Insert slide pads into the top end mast rails between
section-2 and -3, (one on each side of the mast),
with beveled surface facing inward towards section-

3.

NOTE: Before fastening and shimming the slide pad on the

top left side of the mast, install a sequence cable
bracket against the mast under the flatwasher.

21. Thread slide pad attaching bolts, two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes in
outside rail, on top of mast section-2 and into the
slide pad inserts. Thread in enough to hold pad in
place.

22. Shim per instructions in step 7, Mast Section 2 ­Assembly.

23. Insert slide pads into the bottom end mast rails
between section-2 and -3, (one on each side of the
mast), with beveled surface facing out towards sec­tion-2.

24. Thread slide pad attaching bolts, two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes on
inside rail, on bottom end of mast section-3 and into
the slide pad inserts. Thread in enough to hold pad
in place.

25. Shim per instructions in step 7, Mast Section 2 ­Assembly.

26. Slide section-3 out the top of section-2 approxi­mately two (2) feet.

27. Locate one (1) of the chain (bottom) anchor plates
(one with threaded holes horizontally aligned to out­side of bracket). Attach using outer set of holes in

bottom of mast section-3 with two (2) 1/4"-20UNC x
3/4" long bolts, place a flatwasher under head of
each bolt.

28. Locate the remaining narrow chain set (#444) and
attach them to the remaining triangular shaped
anchor plate using the attach pins, flatwashers and
cotter keys.

29. Install the chain/anchor plate assembly into the top
of mast section-3, using the remaining large pin and
pin keeper. Allow to hang out the top of mast sec­tion-3 for later assembly.

30. Insert the threaded the ends of chain assembly
(attached to top of mast section-1), into the opening
between mast section-2 and mast section-3. Slide
the threaded ends through the holes in bottom
anchor plate attached to bottom of mast section-3.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Chains will be adjusted later
in assembly.

31. Assemble chain sheaves (for narrow chain assem-
bly) to top of mast section-3 as follows;

a. Place four (4) of the 1" flatwashers onto one of

the remaining sheave pins. Locate two (2) nar­row chain sheave wheels and slide onto sheave
pin on each side of the flatwashers.

b. Slide two (2) short spacer tubes onto sheave

pin, one each end of sheave pin to outside of
sheave wheels.

c. Place two (2) sheave pin support bars, one each

end of sheave pin onto outside of spacer tubes.
Place a roll pin in the slots at each end of the
sheave pins and align with the cutouts in the pin
support bars.

d. Holding complete sheave wheel assembly, slide

assembly into top of mast section-3 and align
threaded holes in sheave pin support bars with
holes in mast rails.

e. Attach to top of mast section-3 using two (2) 3/

8"-16UNC x 1/2" long socket head-countersunk-

2-28 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

flathead cap screws, each side. Coat threads
with Loctite #171 and tighten.

32. Slide mast section-3 back into section-2 until ends
are even. Check to make sure chain assembly (wide
chains) are seating properly in chain anchor block
chain sheave wheels attached to mast section-2.

MAST SECTION 4 - ASSEMBLY

NOTE: When sliding mast sections together, be careful not

to scratch or score the anodized finish in the slide
pad channels.

33. Carefully slide mast section-4 into section-3 until ends are even.

34. Insert slide pads into the top end mast rails between
section-2 and -3, (one on each side of the mast),
with beveled surface facing inward towards section-

3.

NOTE: Before fastening and shimming the slide pad on the

top left side of the mast, install a sequence cable
bracket against the mast under the flatwasher.

35. Thread slide pad attaching bolts, two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes in
outside rail, on top of mast section-2 and into the
slide pad inserts. Thread in enough to hold pad in
place.

36. Shim per instructions in step 7, Mast Section 2 ­Assembly.

37. Insert slide pads into the bottom end mast rails
between section-2 and -3, (one on each side of the
mast), with beveled surface facing out towards sec­tion-2.

38. Thread slide pad attaching bolts, two (2) 1/4"­20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes on
inside rail, on bottom end of mast section-3 and into
the slide pad inserts. Thread in enough to hold pad
in place.

plate attached to bottom of mast section-4. Loosely
thread two (2) 3/8"-16UNC nuts onto stud threads on
each chain. Chains will be adjusted later in assem­bly.

43. Assemble chain sheaves (for narrow chain assem-
bly) to top of mast section-4 as follows;

a. Locate the remaining sheave pin and slide the

wide tube spacer onto the pin shaft.

b. Place two (2) of the narrow chain sheave wheels

onto the sheave pin on each side of the wide
spacer.

c. Slide two (2) 1" flatwashers onto each end of

sheave pin to outside of sheave wheels.

d. Place two (2) sheave pin support bars, one each

end of sheave pin to outside of space tubes.
Place a roll pin in the slots at each end of the
sheave pins and align with the cutouts in the pin
support bars.

e. Holding complete sheave wheel assembly, slide

assembly into top of mast section-4 and align
threaded holes in sheave pin support bars with
holes in mast rails.

f. Attach to top of mast section-4 using two (2) 3/

8"-16UNC x 1/2" long socket head-countersunk­flathead cap screws, each side. Coat threads
with Loctite #171 and tighten.

NOTE: When sliding mast sections together, be careful not

to scratch or score the anodized finish in the slide
pad channels.

44. Carefully slide mast section-4 into section-3 until
ends are even. Check to make sure chain assembly
(narrow chains) are seating properly in chain anchor
block chain sheave wheels attached to mast sec­tion-3.

MAST SECTION 5 - ASSEMBLY

1. Locate the remaing mast section-5 (platform mount-

ing - mast section). Lay mast section on flat stable
surface.

39. Shim per instructions in step 7, Mast Section 2 ­Assembly.

40. Slide section-4 out the top of section-3 approxi­mately two (2) feet.

41. Locate one (1) of the chain bottom anchor plates

(one with threaded holes horizontally aligned to cen­ter of bracket). Attach using holes in bottom of mast

section-4 with three (3) 1/4"-20UNC x 3/4" long bolts,
place a flatwasher under head of each bolt.

42. Insert threaded ends of chain assembly (attached to
top of mast section-2), into the opening between

mast section-3 and mast section-4. Slide the
threaded ends through the holes in bottom anchor

2. Attach the remaining chain bottom anchor plate

(one with threaded holes aligned at the outside of
bracket). Attach through set of holes in bottom of

mast section-5 with four (4) 1/4"-20UNC x 3/4" long
bolts, place a flatwasher under head of each bolt.

NOTE: The platform mounting section slide pads, are

assembled differently than the slide pads for the
other mast sections. Mast section-5 slide pads may
need to be assemb led/d is assembled sev era l times in
order to determine the co rrect shim stock re quired
for proper fit.

3. Complete the following steps to determine shim stock thickness required for section-5;

3120797 – JLG Lift – 2-29

SECTION 2 - SERVICE PROCEDURES

NOTE: Always use the an even amount of shim material

behind slide pads on both sides of the mast rails.
This will keep mast sections centered in rail chan­nels and prevent any distortion of the section.

a. Use two shim pieces per slide pad, a thick one

and a thin one.

b. Start with a total thickness of approximately

.035" and .075" thick shim stock.

c. Attach shim stock and slide pads to both sides

of mast section-5 using five (5) 1/4"-20UNC x 1­1/4" long, hex head cap screws per side, with
flatwasher under each bolt head. (Assemble

shim stock and slide pad to mast section rail with
shim stock against rail and slide pad with bev­eled side out).

d. Carefully thread the slide pad mounting bolts

with flatwashers through slide pads and shim
stock into threads in mast section-5. Be certain
there are no air gaps between shims, shim and
mast or shim and slide pad when tightened.

NOTE: Mast section-5 in to se cti on-4 f it sh oul d be ver y s nug

but still be able to be pushed together by hand. If too
tight, remove section-5, disassemble slide pad and
reduce thickne ss of shim stock.

e. Begin sliding top of mast section-5 with closed

rail down engaging the slide pads into slide pad

channels at bottom of mast section-4’s open rail.
Continue to push section-5 into section-4 until
BOTTOM ends of mast sections are even.

f. Check mast section for side play. If play exists

use thicker shims dividing thickness equally
between both sides of mast.

g. When mast slide pads are shimmed properly,

there should be no side to side movement of
slide pad in rail channel. Mast sections should
be very snug in channels but still be able to slide
in channel by hand.

4. Slide mast section-5 out even with top of section-4.

5. Insert threaded ends of chain assembly (attached to

top of mast section-3) into the opening between
mast section-4 and mast section-5. Slide the
threaded ends through the holes in bottom chain
anchor plate located on bottom of mast section-5.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Chains will be adjusted later
in assembly.

6. Slide mast section-5 back into mast section-4 until
bottom ends of masts are even. Check to make sure
chain set attached to top of section-3 is seating
properly in cable sheave wheels attached to top of
mast section-4. (Mast section-3 may need to be

restrained to keep it’s slide pads from pushing out
the bottom of mast sections-2).

7. Adjust top and bottom ends of mast sections so they
are all even with each other. At bottom of mast
assembly, thread all chain adjusting nuts on
threaded ends until they are snug against the bot­tom anchor plates and all slack is removed from
chains. Check that chains are seated in their sheave
wheels at top of mast assembly.

8. Assemble the mini covers to the top of each mast
section and the sequencing cables and hardware to
the side of the mast assembly.

9. Assemble the hydraulic cylinder mount to the bot­tom of mast section-1, shim the sides of the mount
between the mount and the rail and place the rein­forcement plate on the outside of the rail to prevent
any distortion of the mast while tightening. Attach
the hydraulic cylinder to the mount. Also attach the
PHP actuator support brackets to the cylinder mount
before inserting the mount into mast section-1.

The mast assembly should now be ready to install on the machines base frame.

2.9 MAST TO BASE FRAME INSTALLATION

1. Using an overhead crane or suitable lifting device

capable of supporting the weight of the base frame,
attach a sling strap or chain to the front crossmem­ber of the base frame, raise base frame.

2. Bring base frame into position in front of mast
assembly, (base frame and mast assembly must be
held at 90° angle to each other).

3. Carefully push mast assembly and base assembly
together until the four (4) holes on bottom rear of
mast align with holes in the base frame mast support
crossmember.

4. Attach mast to base using four (4) 3/8"-16UNC x 1"
long hex head bolts, locknuts and flatwashers,

(place a flatwasher under bolt head and nut and
mount with nuts on inside of frame).

5. Fasten the PHP actuator support brackets to the PHP actuator bracket.

6. Locate the two (2) mast support braces, attach to
the brackets on the base frame using a 3/8"-16UNC
x 1" long hex head bolt, nut and flatwashers each
brace, (place a flatwasher under bolt head and nut

and mount with nuts on inside of frame. Use access
hole in bottom of frame to attach nut inside frame).

7. Before setting machine upright on base, install a

short 90° elbow fitting, flow control valve and
another short 90° elbow fitting on the end of the flow
control valve in the extend (left) port on bottom of
hydraulic cylinder. Install a long 90° elbow fitting on

2-30 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

return (right) port. Use sealant tape on fitting
threads. Cap ports until hydraulic lines are installed.

8. Carefully set machine in an upright position on its base frame wheels.

9. Locate the mast support bracket. Attach mast sup­port bracket to mounting holes halfway up back of
mast using four (4) 3/8"-16UNC x 2-3/4" long hex
head bolts, locknuts and flatwashers. (Place a flat-

washer under bolt head and nut and mount with nuts
on inside of frame).

10. Using a 4 ft. level, ensure mast is set to vertical (plumb) on the base frame.

11. When mast is vertical (plumb), attach support
braces, (bolted to base), to the mast support
bracket, (bolted to mast), using 3/8"-16UNC x 2-3/4"
long hex head bolts, nuts and flatwashers. (Place a

flatwasher under bolt head and nut and mount with
nuts on inside of bracket).

12. After securing mast to base frame, using 4 ft. level
again check that mast is vertical (plumb) on base
frame.

13. Continue installing remaining components to mast
assembly, (i.e. hydraulic pump/motor/reservoir, bat-
tery charger, etc.).

Mast installation should now be complete.

2.10 MAST CHAINS/CABLES AND SEQUENCING CABLES ADJUSTMENT

3. Adjust one mast section at a time starting from the

back (section-3, section-4, etc.) of the mast and
work forward. (i.e.. if three is OK, then jump to four,
etc.)

4. To adjust, elevate the platform until the chain/cable
anchor adjust nuts are accessible at the front and
bottom of each mast section.

NEVER WORK UNDER AN ELEVATED PLATFORM UNTIL PLAT­FORM HAS BEEN SAFELY RESTRAINED FROM ANY MOVEMENT
BY BLOCKING OR OVERHEAD SLING.

5. Start with the mast section which needs adjustment
and loosen the bottom (jam) nut on each chain/
cable.

6. Tighten (to raise mast section), or loosen (to lower
mast section) the adjusting nut against the anchor

plate on each chain/cable. Adjust the nut the
amount required to raise or lower the top of the mast
section to match the side profile shown in Figure 2-

19. when the mast is retracted.

NOTE: It is more important that the (threaded ends) studs

protruding on the adjustments are equal side to side
on a mast section, than it is that the tension in the
chains is equal. The chain equalizers will always

assure equal tension, but if the adjustment isn’t
equal as described, the chains may tend to pull to
one side or t he other.
The threaded end of the chain/cable may need to be
restrained while tightening the adjust nut to keep the
chain/cable from twisting.

Mast Chain/Cable Adjustment

The intention of this procedure is to assure equal load dis­tribution between the individual chains/cables of a mast
section chain/cable set. Also to step each front mast sec­tion up approximately 7/16 in. (12mm) from the section
behind it to allow clearance for the individual mast section
covers.

Adjust using the following procedure;

1. With mast retracted, step into the platform and
bounce your weight up and down a few times to be
certain platform is at the bottom of travel. Be certain
all chain/cable sets are seated in their sheaves prop­erly at the top of each mast section.

2. Then with no load in the platform check the side pro­file of the top of the mast for the amount of adjust­ment necessary to obtain the 7/16 in. (12mm) step
for mast sections-3 and up. (See Figure 2-19.)

NOTE: Mast section-1 is fixed to the base and mast section-

2 is attached to the lift cylinder, these sections
require no ad justment.

7. Retract the mast all the way and check if the top of
the mast sections appear as shown in Figure 2-19.

8. Repeat steps (1) through (7) for remaining mast sec­tions.

9. Once mast section adjustment is completed, apply
loctite #242 to the threads under the (jam) nuts that
were loosened. Then re-tighten the loosened (jam)
nuts until tight against the top (adjust) nut. Chain/
cable should have slight tension but should not be
taut.

10. After all mast adjustments are complete, if neces­sary adjust the bumpers on the underside of the
stock-picker platform so the platform rests slightly
above the base frame when it is lowered and empty.

Sequencing Cable Adjustment

1. Retract mast completely, and check each sequenc-

ing cable on outside of masts for excessive slack.
Adjust only to remove slack from cable.

3120797 – JLG Lift – 2-31

SECTION 2 - SERVICE PROCEDURES

S

p

MAST SIDE PROFILE

CHECK IF OVERALL HEIGHT

OF MACHINE FROM

FLOOR TO TOP OF MAST

IS WITHIN SPECIFICATION

STEP APPROXIMATELY

7/16 in. (12mm)

SECTION-1

SECTION-2

EXTENDED BY

CYLINDER

SECTION-3

EXTENDED BY

EXTENDED BY
CHAIN/CABLE

SEQUENCE CABLE

ADJUST NUT

FIXED

TO BASE

CHAIN

SECTION-4

MAST CHAIN/CABLE ADJUSTER

SECTION-5

(PLATFORM

HEADER SECTION)

EXTENDED BY
CHAIN/CABLE

Note: When

is complete, before
tightening the jam nut
against the adjust nut,

ply Loctite #242 to the

a

threads under the jam nut.

Figure 2-19. Mast Chain/Cable/Sequence Cable Adjustment Components. (Typical)

2. Tighten nylock-nut just enough to remove excessive

slack from sequencing cable. The springs should
not be compressed more than 25% after adjusting.

3. Run mast through several cycles to verify cable/
chain adjustments and ensure no interference exists
between chain anchor brackets and mast.

chain adjustment

.

CHAIN/CABLE

ANCHOR PLATE

ADJUST NUT

JAM NUT

THREADED

CHAIN/CABLE

END

2-32 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

IMPORTANT

2.11 SEQUENCE CABLE REPLACEMENT KIT

A sequence cable replacement kit is available from the
JLG Parts Department to service broken or worn
sequence cables. This kit consists of a replacement
sequence cable with the threaded (top) end attached
same as the top end of the factory cable. Also included is
a clamp (drum/socket type) to secure the bottom end of
the cable. Use the following procedure to install the
replacement cable and clamp kit.

Remove Old Cable

1. Remove the locking nut from the threaded end of

the cable at the top of the mast and then remove the
spring cap, spring, and spacer washers if installed.

2. Slide the threaded top end out of the upper anchor
bracket, then at the bottom end pull the cable out
though the sheave pulley/anchor bracket until it is
completely clear of the machine.

Replacement Cable Installation

1. Be certain the mast is completely retacted and at the

bottom of travel. Check the mast "Side Profile" at the
top of the mast as shown in Figure 2-19., adjust
mast sections to proper height if necessary.

2. To determine where the clamp will be installed at the
bottom of the replacement cable, temporarily
assemble the new replacement cable to the top
cable anchor bracket on the mast using the wash­ers, spring, spring cap and lock nut previously dis­assembled. Thread the lock nut on until
approximately 1/8 in. (3mm) of threads are exposed.

3. At the bottom of the mast, thread the loose end of
the replacement cable through the proper sheave
pulley and through the hole in the sheave pully/
anchor bracket on the mast section ahead of the
sheave pulley.

4. Grasp the cable and pull on the cable until the
spring at the top of the cable is slightly compressed.
Use a black marker to mark the cable on the top
side of the sheave pully/anchor bracket. This will
determine where the clamp (drum/socket) sleeve
will be positioned on the cable.

Clamp Installation (Drum/Socket Type)

IMPORTANT

THE MANUFACTURER OF THE DRUM/SOCKET CLAMP RECOM­MENDS THE USE OF THEIR CABLE CLAMP ASSEMBLY KIT (JLG
P/N - 7023275) TO ASSEMBLE THE CLAMP TO THE WIRE ROPE.
THE KIT CONSISTS OF VISE JAWS TO HOLD THE WIRE ROPE IN
A VISE PROPERLY WITHOUT DAMAGING ANY ROPE STRANDS
AND A PLUG DRIVER TO DRIVE THE PLUG INTO THE CENTER OF
THE WIRE ROPE AND IS ALSO USED TO FORM THE STRANDS OF
THE ROPE DURING ASSEMBLY.

NOTE: The tools in the clamp assembly kit may be frabri-

cated if necessary. The vise clamp consists of vise
jaws with a hole drilled 1/32 in. smaller than the
diameter of the wire rope you are working with (i.e.
1/8 in. rope - 3/32 in. hole.)
The plug driver is a metal tube with a hole in the bot­tom to allow the strands of the wire rope to be
shaped after the plug has been tapped into the cen­ter of the wire rope.

1. Using the recommended vise jaws, clamp the wire
rope into a vise with the bottom edge of the black
mark made on the wire rope resting just above the
vise jaws.

2. Twist the sleeve from the clamp kit onto the rope
until it is flat against the vise jaws at the mark made
made on the wire rope.

DO NOT CUT THE CABLE AT THE MARKED POINT ON THE
CABLE THIS IS ONLY USED AS A REFERENCE FOR POSITIONING
THE CABLE SLEEVE WHICH WILL REST AGAINST THE ANCHOR
BRACKET ONCE INSTALLED.

3120797 – JLG Lift – 2-33

SECTION 2 - SERVICE PROCEDURES

3. Use a suitable tool and cut the cable as shown in the
illustration following. For 1/8 in. cable the recom­mended length is 5/8 in. past the end of the sleeve.

4. Unlay the cable strands by gently forcing a screw­driver between the outer strands to unlay the cable.
When done properly the outer strands will form a
symmetrical basket. Do not straighten out the spiral
lay of the strands, unlay any wires that make up the
strand, or allow the strands to cross each other
inside the sleeve.

6. Reclamp the assembly in the vise on the flats of the
sleeve. Using the plug driver, a metal tube or pliers,
bend the outer strands toward the center strands
enough that the socket can be slipped over all the
strands.

NOTE: When assembling stainless steel parts all threads

must be coated with a dry lubricant or an anti-sieze
lubricant to prevent seizing.

7. Coat the threads of the socket and sleeve with lubri­cant and install the socket by twisting it over the
strands of the cable and engage the threads of the
sleeve with the socket. Tighten until four threads or
fewer are visible. If more than four threads are visi­ble, proof load the cable and retighten the socket fit­ting. (There is no specific requirement for torque.)

5. Install the plug supplied with the kit by placing the
plug in the center of the strands starting with the
small tapered end of the plug. Use a metal tube
(plug driver) and hammer to drive the plug into the
sleeve while assuring that the strands are spaced
somewhat equally around the plug. Drive the plug
until it is firmly seated and no more than 1/3 of the
plug is visible from above the sleeve.

8. Inspect for proper assembly prior to loading the
cable. Strands visible through the inspection hole
are your assurance of a proper assembly.

NOTE: The end of the rope may not be visible in the inspec-

tion hole after loading.

9. Install cable on machine and adjust per instructions
shown previously in Section 2.10, MAST CHAINS/
CABLES AND SEQUENCING CABLES ADJUST­MENT

2-34 – JLG Lift – 3120797

SECTION 2 - SERVICE PROCEDURES

2.12 PREVENTIVE MAINTENANCE AND INSPECTION SCHEDULE

(See Figure 2-3)

The preventive maintenance and inspection checks are
listed and defined in the following table (See Figure 2-3,
this chapter). This table is divided into two basic parts, the

“AREA” to be inspected and the “INTERVAL” at which the
inspection is to take place. Under the “AREA” portion of
the table, the various systems along with the components
that make up that system are listed. The “INTERVAL” por­tion of the table is divided into five columns representing
the various inspection time periods. The numbers listed
within the interval column represent the applicable inspec­tion code for which that component is to be checked.

The checks and services listed in this schedule are not
intended to replace any local or regional regulations that
may pertain to this type of equipment nor should the lists
be considered as all inclusive. Variances in interval times
may occur due to climate and/or conditions and depend­ing on the location and use of the machine.

JLG Industries requires that a complete annual inspection
be performed in accordance with the “Annual Machine
Inspection Report” form. Forms are supplied with each
new machine and are also available from JLG Customer
Service. Form must be completed and returned to JLG
Industries.

IMPORTANT

JLG INDUSTRIES REQUIRES THAT A COMPLETE ANNUAL
INSPECTION BE PERFORMED IN ACCORDANCE WITH THE

“ANNUAL MACHINE INSPECTION REPORT” FORM.

3120797 – JLG Lift – 2-35

SECTION 2 - SERVICE PROCEDURES

Table 2-3. Preventive Maintenance & Inspection Schedule.

AREA ON MACHINE INTERVAL

PLATFORM

Platform Controll er (all functions) 1,11
Placards and D ecals 1,2
Control Tags 1,2
Electrical Cables 1,8
Handrail and Bar Gate 1,4

MAST

Mast Chains and a ll mast component parts 1,4,7,9 12 Mast Section s 1,4,7 Mast Sequencing Cables 1,4,7,9 Speed/PHP Limit Switc hes 1,7,9

BASE FRAME

Batteries 1,3 5 Battery Charge 1 Power Cables To Platform 1,8 Electric Motor/H ydraulic Pump Unit 1 5 Hydraulic Hoses and Fittings 1 5 Hydraulic Oil Reservoir * 3 5 4 Hydraulic Oil Re servoir Breather 6,14 Manual Descent Valve 1,7 Lift Cylinder 1 5,6,13 4 Placards and D ecals 1,2 Wheels and Caste rs 1 8,9 12 Wheel Bearings 8 12 Electric Drive Whee l Motors 1 ,7 Electric Drive Whee l Gear Box ** Torque Limitin g Clutch 1,6,9 Power Switch (Ground Control Box) 1,11 Control Tags 1,2 Hoses and Cables 1,8 Bubble Level Indicator 1,2

* Inspection and Maintenance Code 10 to be performed every two years.

** Change only when serviced, requires 175cc’s to fill.

(10 HRS.)

DAILY

(50 HRS.)

WEEKLY

(200 HRS.)
MONTHLY

(500 HRS.)

3 MONTHS

(1000 HRS.)

6 MONTHS

(2000 HRS.)

1 YEAR

Inspection and Maintenance Codes:

1. Check for proper and secure installation.

2. Check for visible damage and legibility.

3. Check for proper fluid level.

4. Check for any structural damage; cracked or broken

welds; bent/warped surfaces; broken cable strands.

5. Check for leakage.

6. Check for presence of excessive dirt or foreign

material.

7. Check for proper operation and freedom of move­ment.

8. Check for excessive wear or damage.

9. Check for proper tightness and adjustment.

10. Drain, clean and refill.

11. Check for proper operation while pump/motor is

running.

12. Check for proper lubrication.

13. Check for evidence of scratches, nicks or rust and

for straightness of rod.

14. Check for condition of element; replace as neces­sary.

2-36 – JLG Lift – 3120797

SECTION 3 - TROUBLESHOOTING

SECTION 3. TROUBLESHOOTING

3.1 GENERAL

This section contains troubleshooting information to be used for locating and correcting most operating problems. If a prob­lem should develop which is not presented in this section or which is not corrected by listed corrective actions, technically
qualified guidance should be obtained before proceeding with any maintenance.

3.2 TROUBLESHOOTING INFORMATION

Troubleshooting procedures applicable to this machine are listed and defined starting with Section 3.5, TROUBLESHOOT­ING SECTION - TABLE OF CONTENTS in this section of the manual.

Each malfunction within an individual group or system is followed by a listing of probable causes which will enable determi­nation of the applicable remedial action. The probable causes and the remedial action should, where possible, be checked
in the order listed in the tables.

It should be noted that there is no substitute for a thorough knowledge of the equipment and related systems.
It should be recognized that the majority of the problems arising in the machine will be centered in the hydraulic and electri-

cal systems. For this reason, every effort has been made to ensure that all likely problems in these areas are given the fullest
possible treatment. In the remaining machine groups, only those problems which are symptomatic of greater problems
which have more than one probable cause and remedy are included. This means that problems for which the probable
cause and remedy may be immediately obvious are not listed in this section.

The first rule for troubleshooting any circuit that is hydraulically operated and electrically controlled is to determine if the cir­cuit is lacking hydraulic oil and electrical control power. This can be ascertained by overriding the bypass valve (mechani-
cally or electrically) so that oil is available to the function valve, then overriding the function valve mechanically. If the function
performs satisfactorily, the problem exists with the control circuit.

3.3 HYDRAULIC CIRCUIT CHECKS

(See Figure 3-4.)

The first reference for improper function of a hydraulic system, where the cause is not immediately apparent, should be the
Hydraulic Diagram Circuit. The best place to begin the problem analysis is at the power source (pump). Once it is deter­mined that the pump is serviceable, then a systematic check of the circuit components, would follow.

NOTE: For aid in troubleshooting, refer to Figure 3-4. for HYDRAULIC DIAGRAM circuit.

3.4 ELECTRICAL CIRCUIT CHECKS

General

The drive system on the VP series machine requires a microprocessor controlled electrical circuit to operate smoothly and
accurately. All platform control functions are relayed to various machine components (i.e. platform up/down, drive functions,
etc.) through the (MC-1) microprocessor box (mounted under the battery charger support bracket).

To help diagnose any problems with the components associated with the microprocessor, the MC-1 is designed with an
internal fault messaging system which is displayed by LED flash sequences on the platform controller. When operating nor­mally the LED panel on the platform controller (center LED strip) indicates the battery voltage status using ten (10) green
LEDs. If a malfunction occurs to any of the drive components, the platform controller, or the MC-1 unit itself, these LEDs will
flash a fault code (Warning or Error type) to help locate the problem area. The possible causes of fault codes are outlined in
the following sub-sections of this chapter, see Table 3-1 and Table 3-2.

NOTE: For aid in troubleshooting electrical problem, refer to Figure 3-3. for an ELECTRICAL DIAGRAM of the various circuits.

Also a pictorial overview of the Section, see Figure 3-2. “Pictorial Overview of VP Electrical System”.

3120728 – JLG Lift – 3-1

SECTION 3 - TROUBLESHOOTING

Figure 3-1. LED Battery/Fault Code Indicator Strip

LED INDICATOR STRIP

on Platform Controller Box.

LED Indicator Strip

When the machine is powered up, all function inputs should be open. If any function is active on power up, all functions will
be made inoperative and a fault will be indicated at the platform controller box LED strip.

This strip has ten (10) green LEDs and is located on the platform controller box between the function touch pad buttons. See
Figure 3-1.

Fault Code Reference Tables

Their are two types of fault codes which can occur to indicate a problem with the machine, these are WARNING codes and
ERROR codes.

The fault codes can occur either at machine power up or during operation of the machine.

WARNING Codes

(See Table 3-1.)

The WARNING will be indicated for 4 seconds and will be repeated every minute if the problem is not corrected. An audible
three beeps indication is given at the beginning of each warning displayed. WHEN A WARNING CODE IS INDICATED THE
MACHINE WILL USUALLY FUNCTION, however some machine functions may be disabled. See Table 3-1. for explanation of
WARNING codes.

ERROR Codes

(See Table 3-2.)

An ERROR is indicated by an audible beep and continuously fast flashing LED bar. The number of fast (rapidly) flashing
LEDs indicate the particular error message. AN ERROR CONDITION WILL DISABLE THE MACHINE until the problem is cor­rected. The ERROR message is only reset by turning off the system, however if the problem has not been corrected the
ERROR will be indicated again at machine power-up. See Table 3-2. for explanation of ERROR codes.

NOTE: As shown in the following WARNING and ERROR co de tables, a s pecific number of LEDs fla shing ca n indicat e more

than one WARNING or ERROR code. These tables suggest specific areas to check as the probable cause for the fault
code which has occured. The fault code number is shown in the first column of the table and the number of LEDs flash­ing on the platform controller LED strip is shown in the second column of the table.

3-2 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-1. MC-1 WARNING CODES

(Indicated by 3 beeps, then slow flashing LED’s)

WAR NING

CODE

010

LED’S

FLASHING

PROBABLE CAUSE REMEDY

Enter Code - Security Code has been activated and
must be entered before operation

Enter Code or deactivate using MC-1 configuration
software.

1 8 Charger Connected Unplug Charger

32

32

32

32

Brake Status Switch Open - Parking brake manually
released

Brake manual release lever obstr ucted (located at
drive motor brake)

Defective parking brake status switch (located at
drive motor brake)

Defective pin 11 at X105 (BRN wire) connection or
improper wiring

Reset Parking Brake

Clear obstruction and reset lever

Replace Switch

Properly attach wires or pin

3 2 Improper wiring at parking brake status switch Properly attach wires

32

45

56

Improper wiring from parking brake status switch to
ground

Configuration Lost - Drive Characteristic has
changed

Current Measurement faulty - Drive characteristic
may have changed

Properly attach wires

Reprogram using MC-1 software

Cycle on-off and reprogram if necessary

6 7 High Temperature in controller Reduce power
7 7 Motor Stalled Check drive wheels and motors
9 1 Battery Low ( < 18v) and power reduced Charge Batteries

12 9 Speed Control Potentiometer defective Replace Joystick

13 4

13 4

13 4

14 3

Drive Cutout Input Open - PHP bar must be down to
drive while elevated

PHP bar is down, but drive is disabled - Defective wir­ing at D-connector

PHP bar is down, but drive is disabled - Defective
ground wiring

PHP bar is down, but drive is disabled - Defective
switch

Lower PHP

Properly attach wire (RED/BLU) or pin 12 of X105
connector

Properly attach wires

Replace switch

14 3 Tilt Switch open - Slope greater than 2 degrees Lower Platform and move to level ground

14 3

No Tilt Switch - open circuit at Pin 2 of X101 (WHT
wire)

Properly attach pin or wire connections

14 3 No Tilt Switch - open circuit to ground Check ground wire connections (BLK1 wire)
25 ---- Joystick E. Stop Counter Controller Log Only
26 ---- Configuration Access Counter Controller Log Only

3120728 – JLG Lift – 3-3

SECTION 3 - TROUBLESHOOTING

(Indicated by rapid LED flashing and periodic beep)

Table 3-2. MC-1 ERROR CODES

ERROR

CODE

LED’S

FLASHING

PROBABLE CAUSE REMEDY

0 8 System Overvoltage - Charger Unplug Charger
0 8 System Overvoltage - Driving down long steep grade Operate ground controls to reduce voltage
1 7 Controller Overtemperature Turn unit off and allow to cool

28

28

Drive Motor Plug - Open Circuit - check connectors
X103 & X104

Drive Motor Plug - Open Circuit - check motor con­nections at motor

Properly attach wires or pins A1 & A2

Properly attach wires or pins (WHT & BLK wires)

3 6 Brake Safety Relay Replace Controller
4 2 Brake Shor t Circuit Replace Brake

52

52

52

62

Brake Left Open Circuit - D-connectors to X103 &
X104 switched

Brake Left Open Circuit - Check pins 3 & 5 of X103
and brake wires

Brake Left Open Cir cuit - Check brake wires or plug at
drive motor

Brake Right Open Circuit - Check pins 2 & 5 of X104
and brake wires

Switch D-connectors - Left Motor to X103; Right
Motor to X104

Properly attach wires or pins

Properly attach wires or pins

Properly attach wires or pins

62

Brake Right Open Circuit - Check brake wires or plug
at drive motor

Properly attach wires or pins

7 2 Brake Open Circuit on one or both brakes See above
8 9 Switch Shor t Circuit (Joystick) Replace Joystick Box
9 6 Power Circuit Defect Replace Controller

10 1 Battery Low (< 16.5 v) Charge Battery

11 9

Check pins & wire connections at X102 & joystick
box connector

Properly attach wires or pins

11 9 Joystick defective Replace Joystick Box

12 8

Check pins & wire connections at X102 & joystick
box connector

Properly attach wires or pins

12 8 Joystick Box Replace Joystick Box

16 7

Current Limiting - Motor Shor t Circuit - Gearmotor
defective

Replace Gearmotor

21 6 36v supply Replace controller

24 5

Configuration Lost Reprogram using MC-1 software, if error reoccours

then replace controller

25 6 RAM ROM Replace controller

3-4 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-2. MC-1 ERROR CODES

(Indicated by rapid LED flashing and periodic beep)

ERROR

CODE

LED’S

FLASHING

PROBABLE CAUSE REMEDY

If voltage @ pin 5 (RED2) of X101 is 20v w/24v @ Batter y or if ground controls and operating lif t up clears
error:

26 6

Defective main contactor Replace main contactor
Battery cables loose or corroded Clean & tighten battery cables

26 6

If 0v @ pin 5 of X101, check connection @ pin 7 &
14 of X102

Properly attach wires or pins

26 6 Connection @ pin 5 of X101 bad Properly attach wires or pins
26 6 Defective Power Relay Replace Relay
26 6 Defective Power Relay ground wire Properly attach wire

27 6

27 6

27 6

Safety Circuit - Joystick - check pin 6 @ X102 (Red
Wire)

Safety Circuit - Joystick - check pin 3 @ joystick
connector (Red Wire)

Defective Joystick - Normal voltage @ pin 6 of X102
(Red Wire): Joystick centered 5v, Joystick not cen-

Properly attach wire or pin

Properly attach wire or pin

Replace Joystick

tered 0v
27 6 Safety Circuit - Defective Controller Replace Controller
28 6 Current Measurement Replace Controller
29 6 Drive Circuit Left - Defective Controller Replace Controller
31 6 Drive Circuit Right - Defective Controller Replace Controller

32 1

Output driver defect - check for short in Hourmeter,

Horn, Alarm or Power Relay

Replace defective component

32 1 Output Driver Defective - Defective Controller Replace Controller

35 8

35 8

Communication Error - Check Pins 5 & 13 of X102

(Orange & Blue Wires)

Communication Error - Check Pins 4 & 5 at Joystick

(Orange & Blue Wires)

Properly attach wires or pins

Properly attach wires or pins

35 8 Defective Joystick Replace Joystick
35 8 Defective Controller Replace Controller
36 6 Watch Dog Replace Controller
38 6 EEPROM Replace Controller
39 6 Software Error Replace Controller

3120728 – JLG Lift – 3-5

SECTION 3 - TROUBLESHOOTING

BEACON

POT-HOLE

PROTECTION

BATTERY
(LEFT SIDE)

HORN

(–

)

(+

ALARM

HOURMETER

BATTE RY
(RIGHT SIDE)

(+

)

(–

)

TO PUMP
MOTOR
SOLENOID

)

F

R

O

C

M

O

X1

N

N

0

E

1

C

T

O

R

PUMP ST ART

CONTA CT OR

MANU AL
OVERRIDE/
LIFT DOW N

VALVE

TO
BATTERY
TERMINAL

PUMP/MOTOR
ASSEMBLY

DUMP

VALVE

GROUND
CONTROL
BOX

LIMIT

SWITCHES

Figure 3-2. Overview of Standard Electrical System Components. (Sheet 1 of 2)

MAIN

CONTA CTO R

RELAY

5

10

R

X

O

T

M

C

O

E

R

N

F

N

O

C

C

F

O

R

N

O

T

R

M

A

E

C

L

T

A

O

Y

R

3-6 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

TO

BA TTER Y

TERMINAL

BA TTER Y

TERMINAL

S

CONTROLLER BO X

LAPTOP COMPUTER

at X105 port on the MC -1 controller box

Requires P/N-2900868 Configuration Kit.)

X104

X101

X105

X103

(remove existing connector

and plug-in the laptop computer.

TILT
SENSOR
SWITCH

USE WIRING

DIAGRAM

FIGURE 3-3.

THIS SECTION

OF THE

MANUAL WITH

THIS PICTORIAL

WIRING DIAGRAM

ELEVATION

LIMIT

SWITCH

F

R

O

M

X

1

0

C

O

N

1

N

E

C

T

O

R

BATTERY

CHARGER

CUTOUT

SWITCH

TO

PLA TFORM

CONTROL

BOX

+

TO

5

0

1

R

X

O

M

T

O

C

R

E

F

N

N

O

C

GROUND

CONTROLS

SWITCH

(LIF T UP/LIFT DOWN)

GROUND

CONTROLS

RELAY

EXTERNAL

DRIVE/HORN

RELAY

CONT ACT OR

RELA Y

T

O

M

I

A

N

O

C

T

N

C

A

O

T

R

L

E

Y

A

PLATFO RM

CONTROLLER

BRAKE

RELEASE

WIRING

BRAKE

RELEASE

WIRING

R

BRAKE LIMIT

SWITCH

WIRING

DRIVE MOTO R

POW ER LEA DS

MOTOR/BRAKE

ASSEMBLY

(LEFT SIDE)

Figure 3-2. Overview of Standard Electrical System Components. (Sheet 2 of 2)

MC-1

DRIVE MOTOR

POW ER LEAD

MOT OR/BRAKE

ASSEMBL Y

(RIGHT SIDE)

3120728 – JLG Lift – 3-7

SECTION 3 - TROUBLESHOOTING

PINS USED FOR
COMMUNICATION
TO SERIAL PORT
ON LAPTOP OR PC.

X105
RX DO - RECEIVE DATA
TX DO - TRANSMIT DATA
GROUND
LIFT UP
LIFT DOWN
PUMP CONTACTOR
DRIVE C UTOUT
BRAKE STATUS
HORN
ALARMS
HOURMETER

X101
B+
B+ CONTROL
MAIN POWER DISCONNECT
ELEVATION SWITCH
TILT CUTOUT
CHARGER INTERLOCK
B –

X102
B+
EMERGENCY S TOP
CAN-LO
CAN-HI
CENTER DETECT

B–
EMERGENCY S TOP

PIN

7
8

13

4
6

5
12
11
15
14

3

PIN

A1

3

5

1

2

4
A2

PIN

15
14
13

5

6

1

7

X104 – RIGHT MOTOR
MOTOR 1
MOTOR 2
BRAKE 1
BRAKE 2

X103 – LEFT MOTOR
MOTOR 1
MOTOR 2
BRAKE 1
BRAKE2

PIN

A1
A2

5

2

PIN

A1
A2

5

3

X105 X101 X104

X102 X103

END VIEW OF MC-1 BOX

SHOWING X CONNECTOR LOCATION

4933172_A

Figure 3-3. VPSP Electrical Diagram. (Sheet 1 of 2)

3-8 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

4933172_A

Figure 3-3. VPSP Electrical Diagram. (Sheet 2 of 2)

3120728 – JLG Lift – 3-9

SECTION 3 - TROUBLESHOOTING

CYLINDER

PRES.
COMPENSATED
FLOW VALVE

EXTEND TUBE

SOLENOID
TWO POSITION/TWO
WAY DUMP VALVE

FILTER/
SCREEN

RETURN TUBE

SOLENOID
WITH
MANUAL
OVERRIDE

FILTER/SCREEN

CHECK
VALVE

ADJ. RELIEF
VALVE

PUMP ENDHEAD

MOTOR

TANK

Figure 3-4. Hydraulic Diagram. (VPSP)

3-10 – JLG Lift – 3120728

PUMP

FILTER/SCREEN

1282953

SECTION 3 - TROUBLESHOOTING

3.5 TROUBLESHOOTING SECTION - TABLE OF CONTENTS

OHM RATINGS FOR VARIOUS COMPONENTS PAGE

Ohm Ratings for Various Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

MAIN POWER CIRCUIT TROUBLESHOOTING

Unit Will Not Power Up From Ground Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

No Power At Platform Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

DRIVE TRAIN TROUBLESHOOTING

Won’t Drive (Platform Lowered Or Elevated). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

Won’t Drive (Platform Elevated Only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Won’t Climb Grade. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20

Drives In Opposite Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21

Will Only Drive A Short Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

Won’t Drive Straight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

Noise From Drive Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

MAST TROUBLESHOOTING

Platform Will Not Lift Up Using Platform Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

Platform Will Not Lower Using Platform Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

Platform Will Not Lift Up From Ground Control Toggle Switch . . . . . . . . . . . . . . . . . . . . . . . . . 3-30

Platform Will Not Lower From Ground Control Toggle Switch . . . . . . . . . . . . . . . . . . . . . . . . . 3-31

Platform Will Not Lower Manually . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

Platform Lift Up And Down Jerky. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

Mast Noisy When Lifting And Lowering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

Platform (Mast) Won’t Stay Elevated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35

Platform (Mast) Descends Too Slowly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

HYDRAULIC LEAK TROUBLESHOOTING

Miscellaneous Hydraulic Leak Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

BASE FRAME COMPONENTS TROUBLESHOOTING

Caster Wheels Not Operating Freely . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

Pot Hole Protection (PHP) Bars Will Not Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

3120728 – JLG Lift – 3-11

SECTION 3 - TROUBLESHOOTING

3.6 OHM RATINGS FOR VARIOUS COMPONENTS

The following table contains ohm ratings for various VP Series machine components.

Table 3-3. Ohm Ratings for Various Components

COMPONENT NOMINAL RESISTANCE @ TEMPERATURE RESISTANCE RANGE POSSIBLE

Main Contactor 46.8ohm - 57.2ohm @ 68deg F 35.7ohm - 67.3ohm

Pump Motor 0.2ohm - 0.4ohm @ 77deg F 0.12ohm - 0.49ohm

Pump Relay 16.0ohm - 17.6ohm @ 77deg F 9.9ohm - 21.8ohm

Brake Coil 44.7ohm - 52ohm @ 68deg F 31.4ohm - 65.3ohm

Drive Motor (Bodine) .1 to .3ohm

(Can change depending on the rotation of the

armature and temperature.)

N/A

3-12 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

3.7 MAIN POWER CIRCUIT TROUBLESHOOTING

Unit Will Not Power Up From Ground Control

Overview Of Procedure

The following procedure tests the circuits from the Battery (+) terminal through the Ground Control Box and to the Main
Contactor Relay and Main Contactor for 24 volts or more. Also the Lift Up/Down Relay circuit is tested.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Battery connections clean and tight.

• Key switch positioned to Ground (GRND) control.

• Emergency stop switch pulled out. (Reset Position)

Table 3-4. Unit will not Power Up From Ground Control.

STEP ACTION SPEC YES NO

1. Check the 5 amp inline fuse on the Red 1-1 wire from the batter y (+)
terminal to the ground control box, key switch.
(Under pump/motor cover).

Ground Control Box Assembly (Disassembled)

2. Is there 24 volts or more reading at the key switch, terminal B.

3. Check for 24 volts or more on the Yel/Red, 2-7 wire from the key

switch to the E-stop switch.

4. Check for 24 volts or more on the Yel/Red, 2-8 wire from the E-stop
to the Ground Control Relay, ter minal 86.

5. Check for 24 volts or more on the Yel/Red, 2-4 wire from the E-stop
to the Main Contactor Relay, terminal 87.

Main Contactor Circuit

6. Check for 24 volts or more on the Yel/Red, 2-4 wire from the Main
Contactor Relay, terminal 87 to the Main Contactor.

7. Did Main Contactor close? — Go to Step 9 Go to Step 8

8. Is the Black ground wire connection from the Main Contactor to

ground OK?

9. At this point, 24 volts should be present at the following terminal
points; • Terminal 86 on the Ground Control Relay.

• Main Contactor, Yel/Red, 2-4 wire.

10. With Main Contactor engaged, 24 volts or more should be present at
the following terminal points;

• Pump Motor - 21’ cable #1.

• Yel/Red, 2-6 wire on the Pump Contactor.

• Yel/Red, 2-6 wires on the Lift Up/Down Relay.

24 volts OK, go to Step 2 Replace Fuse

Check Wiring

2 4 v ol ts G o t o S te p 3

from Battery to

Terminal B.

Repair or Replace

Repair wiring or

2 4 v ol ts G o t o S te p 4

Replace Key

Switch

Repair wiring or

—Go to Step 5

Replace E-Stop

Switch

Repair wiring or

—Go to Step 6

Replace E-Stop

Switch

Repair wiring or

—Go to Step 7

Replace Main

Contactor Relay

—

Replace Main

Contactor

Repair Ground

Wiring

———

———

3120728 – JLG Lift – 3-13

SECTION 3 - TROUBLESHOOTING

No Power At Platform Control

Overview Of Procedure

The following procedure checks voltage and ground starting from the power source (batteries) through the ground control
station (key switch/E-stop) to the MC-1 box and finally to the platform control.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Keyswitch is turned to PLAT. (Platform)

• Both Emergency Stop Switches Reset (Ground/Platform). (Out)

• Connection of X102 Cable from MC-1 box to Platform Control, secure on both ends.

Table 3-5. No Power At Platform Control.

STEP ACTION SPEC YES NO

1. Check if the inline 5 amp fuse is blown on the Red, 1-1 wire at the
ground control station. (Ground control cover must be removed)

2. Check voltage to the Yel/Red, 2-2 wire at the MC-1 box, X101 con­nector, pin 3.

3. Check for Ground to the Black wire at the MC -1 box, X101 connec­tor, pin A2.

4. Check voltage to the Yel/Red, 2-3 wire at the MC-1 box, X101 con­nector, pin 5.

5. Check voltage to the Yel/Red, 2-5 wire at the MC-1 box, X101 con­nector, pin A1.

6. Check voltage to the Yel/Red, 2-2 wire at the MC-1 box, X101 con­nector, pin 3, from the Power Relay pin 30.

7. Check voltage to the Power Relay, pin 87. 24 volts Go to Step 9 Go to Step 8

8. Check for Ground to the Power Relay on the Black wire pin 85, to

Ground.

9. Check voltage to the Yel/Red, 2-4 wire at the Main Contactor from
the Power Relay, pin 87.

10. Check for Ground, on the Black wire to the Main Contactor.

11. Check voltage at the Battery Cable from Battery to Main Contactor.

12. Check voltage to the Yel/Red, 2-5 wire at the Main Contactor.

— If OK, go to Step 2 Replace Fuse

Per form the E-

2 4 v ol ts G o t o S te p 3

Stop/Key Switch

Circuit Check

(Table 3-17)

Check connec-

Ground Go to Step 4

tion/wiring

between Battery

and X101, Pin A2

2 4 v ol ts G o t o S te p 5

Replace MC-1

Control Box

24 volts Go to Step 13 Go to Step 6

Check the wire

24 volts Go to Step7

between the

Power Relay and

Connection

Check wiring to

Ground Replace Relay

Ground

Connection

24 volts Go to Step 10

Check the Yel/

Red, 2-4 Wiring

Check wiring to

Ground Go to Step 11

Ground

Connection

24 volts Go to Step 12

24 volts

Check Yel/Red 2-

5 Wire

Check Batter y

Cable

Replace Main

Contactor

3-14 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-5. No Power At Platform Control.

13. Check voltage on the Red/Blk wire at the MC-1 box, X102 connec-

tor, pin 15, to the Platform Control.

14. Check for Ground on the BRN wire at the MC-1 box, X10 2 connector,
pin 1, to the Platform Control.

15. Check voltage on the Red/Blk wire, pin 9 on the Platform Control
box.

16. Check for Ground on the BRN wire, pin 8 on the Platform Control
box.

24 volts Go to Step 14

Ground Go to Step 15

24 volts Go to Step 16 Replace Cable

Ground

Replace Platform

Control

Replace MC-1

Box

Replace MC-1

Box

Replace Cable

3120728 – JLG Lift – 3-15

SECTION 3 - TROUBLESHOOTING

3.8 DRIVE TRAIN TROUBLESHOOTING

Won’t Drive (Platform Lowered Or Elevated)

IF MACHINE WON’T DRIVE ONLY WHEN PLATFORM IS ELEVATED, SEE SECTION 4.4

Overview Of Procedure

The following procedures check the components and circuits that feed data to the MC-1 Controller box assuring it is receiv­ing the proper signals and conditions before engaging the machines’ drive motors.

Check For These Obvious Conditions First:

• Joystick Powered On

• Unit will Lift & Lower Platform

• Machine is not Tilted - (3 LEDs flashing at joystick control)

• PHP Device is not Obstructed - (4 LEDs flashing at joystick control)

• Brakes are not Released - (2 LEDs flashing at joystick control)

• Charger is not Plugged In - (8 LEDs flashing at joystick control)

STEP ACTION SPEC YES NO

1. Check for ground from elevation limit switch in the X101 connector,
pin 1 (49-5) at MC-1 box.

Table 3-6. Won’t Drive. (Platform Lowered or Elevated)

Check Elevation

—Go to Step 2

Circuit (Table 3-7)

2. Check for ground from charger circuit wire in the X101 connector,
pin 4 (49-7) at MC-1 box. (Perform this check with the charger

— Faulty Charger Go to Step 3

unplugged)

3. Check for ground from brake limit switches in the X105 connector,
p in 1 1 at M C -1 b ox .

—Go to Step 4

Limit Switch Cir-

cuit (Table 3-8)

4. Check that brakes are releasing, (2 LEDs) when joystick is enabled
& moved forward.

—

Check Drive

Motor Circuit

Switch/Circuit

(Table 3-9)

Table 3-7. Elevation Switch Circuit Check

• Perform these checks at the elevation switch which is located inside the top of mast section-1.

• Check with mast lowered.

STEP ACTION SPEC YES NO

1. Check for ground into the switch from ground connection.

2. Check for ground out of switch to the 49-5 wire.

3. Check for ground from switch to X101, Pin 1.

—Go to Step 2

—Go to Step 3

——

Adjust/Replace

Repair Wire or

Limit Switch

Check Brake

Check Brake

(Table 3-10)

Repair

Connection

Switch

Connection

3-16 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-8. Brake Limit Switch Circuit Check

STEP ACTION SPEC YES NO

1. Check for ground into the switch from the ground connection on the
left brake limit switch.

2. Check for ground on the 49-4 wire coming out of left brake limit
switch.

3. Check for ground on the 49-4 wire going into the right brake limit
switch.

4. Check for gound on the 49-3 side of the right brake limit switch.

—Go to Step 2

—Go to Step 3

—Go to Step 4

—

Replace

MC-1 box

Repair

Connection

Adjust/Replace

Switch

Repair/Replace

49-4 wire

Repair wire or

Connection

Table 3-9. Drive Motor/Circuit Check

• Perform these checks with the joystick enabled and pushed to the full forward position.

STEP ACTION SPEC YES NO

1. Check for 24 volts at the driv e motor on the 55-3 wire o n the right
motor and the 55-7 wire on the left drive motor. (Positive Side)

2. Check for 24 volts at the 55-3 wire at the X104 connector, pin A2 (for
right motor) and the 55-7 wire at the X103 connector, pin A1 (for lef t
motor).

Table 3-10. Brake Switch/Circuit Check

24 volts

24 volts

Prob lem wit h

Motor

Check wiring and

connections

Go the Step 2

Problem in MC-1

box or Joystick

• Perform these checks with the joystick enabled and pushed to the full forward position.

STEP ACTION SPEC YES NO

1. Check for 24 volts at the wiring connectors on the 55-4 wire on the
right drive motor brake unit and the 55-8 wire on the left drive motor
brake unit.

2. Check for 24 volts at the 55-4 wire at the X104 connector, pin 5(for
right motor) and the 55-8 wire at the X103 connector, pin 5 (for left
motor).

24 volts

24 volts

Clean, Gap or

Replace Brake

Unit

Check wiring and

connections

Go to Step 2

Problem in MC-1

box or Joystick

3120728 – JLG Lift – 3-17

SECTION 3 - TROUBLESHOOTING

Won’t Drive (Platform Elevated Only)

Overview Of Procedure

The following procedures check the components and circuits that feed data to the MC-1 Controller box assuring it is receiv-

ing the proper signals and conditions before engaging the machines’ drive motors.

Check For These Obvious Conditions First:

• Joystick Powered On

• Unit will Lift & Lower Platform

• Machine is not Tilted - (3 LEDs flashing at joystick control)

• PHP Device is not Obstructed - (4 LEDs flashing at joystick control)

• Brakes are not Released - (2 LEDs flashing at joystick control)

• Charger is not Plugged In - (8 LEDs flashing at joystick control)

Table 3-11. Won’t Drive with Platform Elevated

STEP ACTION SPEC YES NO

1. Check for ground on tilt circuit at MC-1 box, X101 connector, pin 2,
(O/R, 49-6 wire).

2. Check for ground on PHP circuit at MC-1 box, X105 connector, pin
12, (O/R, 49-1 wire).

—Go to Step 2

—

Prob lem in MC -1

controller box

Check Tilt Sensor

Circuit (Table 3-

12)

Check PHP

Switch Circuit

(Table 3-13)

Table 3-12. Tilt Sensor Circuit Check

• No ground at MC -1 box, X101 connector, pin 2, (O/R, 49-6 wire).

STEP ACTION SPEC YES NO

1. Is tilt sensor light on showing a tilt conditio n, even though machine is
within tilt limit.

2. Check for ground on the Black wire (di rect to ground) running into tilt
sensor. (Continuity to B-)

3. Check for 24 volts at the Green to (Y/R, 2-5) wire from the main con­tactor relay.

—

—Go to Step 3

—Go to Step 4

Adjust tilt sensor

if necessary

Go to Step 2

Connection

Check Connec-

tion to Main Con-

tactor Relay

4. Check for ground on the White to (O/R, 49-6) wire at connector.

—

Repair connec­tion at the X101
connector end/

broken wire O/R

Replace

Tilt Sensor

49-6

Repair

3-18 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-13. PHP Limit Switch Circuit

• No ground on PHP circuit at MC-1 box, X105 connector, pin 12, (O/R, 49-1 wire).

• With PHP bars up.

STEP ACTION SPEC YES NO

1. Check for ground on Black wire (direct to ground) on the right side
PHP limit switch. (Continuity to B –)

2. Check for ground on O/R, 49-2 wire to left PHP limit switch.

3. Check for ground on O/R, 49-1 wire to MC-1 box, X105 connector,

pin 12.

—Go to Step 2

—Go to Step 3

Repair connec-

—

tion at the X105

connector end

Connection

Adjust/Replace

Right Switch

Adjust/Replace

Left Switch

Repair

3120728 – JLG Lift – 3-19

SECTION 3 - TROUBLESHOOTING

Won’t Climb Grade

Overview Of Procedure

The following procedure checks the drive motor and attached components for component failure, misadjustment due to
wear.

Check For These Obvious Conditions First:

• Batteries are Fully Charged (24 Volts)

• Speed Control is Set to Maximum

• Is Grade within the Maximum Allowable Specification of 15% Grade (8.5 degrees)

• Does the Travel Surface allow for Proper Drive Wheel Traction

• Is Platform Load within the Maximum Rated Capacity

Table 3-14. Won’t Climb Grade

STEP ACTION SPEC YES NO

1. Does machine drive straight on a level surface?

2. Are both the left and right drive motor, slip-clutches, located
between the drive motor and the drive wheels, working properly?

3. Do the left and right drive motor brakes release properly and allow
the drive wheels to rotate freely ?

4. Check the amperage output of the on the drive motor leads. They
should not exceed 70 amps while pulling a grade.

5. Check the condition of the drive motor brushes.

6. If all above is OK, Drive motors are working properly. Consult Fac-

tory.

—Go to Step 2

—Go to Step 3

—Go to Step 4

Controller will

—

Shut Drive Down

and will flash a 7

LED Code

— OK, go to Step 6

———

Refer to Machine

Won’t Drive

Straight

(Table 3-18)

Repair, Replace

or Adjust Slip

Clutch

Dragging?

Repair, Replace

or Adjust Brakes

Go to Step 5

Worn down,

replace brushes

or drive motor

3-20 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Drives In Opposite Direction

Overview Of Procedure

The following procedure checks that both the drive motor power wire connections correctly installed and are secure and
tight. Also that the joystick control assembly for proper installation at the platform control box.

Check For These Obvious Conditions First:

• If the Left Drive Motor (X103) connector is switched with the Right Drive Motor (X104) connector at the MC-1 box, you will
immediately get an 2 LED flashing Error Code at the Platform Control when the machine is powered up.

• Check Joystick Calibration (See Procedure in Service Manual, Section-2).

Table 3-15. Drives In Opposite Direction

STEP ACTION SPEC YES NO

1. Check the connection of the Orange, 55-3 wire to the right drive
motor at both ends;

• At the X104 connector on the MC-1 box, pin A1.

—Go to Step 2

• And the Black wire at the Drive Motor end.

2. Check the connection of the Orange, 55-6 wire to the right drive
motor at both ends;

• At the X104 connector on the MC-1 box, pin A2.

—Go to Step 3

• And the White wire at the Drive Motor end.

3. Check the connection of the Orange, 55-7 wire to the l eft drive motor
at both ends;

• At the X103 connector on the MC-1 box, pin A1.

—Go to Step 4

• And the Black wire at the Drive Motor end.

4. Check the connection of the Orange, 55-10 wire to the left drive
motor at both ends;

• At the X103 connector on the MC-1 box, pin A2.

—Go to Step 5

• And the White wire at the Drive Motor end.

5. Is platform control box under warranty? ** — Order New One Go to Step 6

6. Internal to the platform control - check that the joystick assembly

inside the platform control has not been installed backwards.

7. Internal to the platform control - check that the joystick assembly
wiring to the platform control circuit card is not wired backwards.

—

—

Re-install
Correctly

Re-install
Correctly

* Repair or

Replace

Connection

* Repair or

Replace

Connection

* Repair or

Replace

Connection

* Repair or

Replace

Connection

Go to Step 7

Consult Factory

* Note: If the Orange, 55-3 or 55-6 wires to the right drive motor in the X104 connector or the Orange, 55-7 or 55-10 wires to

the left drive motor in the X103 connector at the MC-1 controller are crossed up that drive motor will run backwards.

** Note: If platform controller is not under warranty, the internal components of the platform controller are replaceable and

can be ordered and replaced seperately from the complete platform control box. See procedures in Section-2 of
this Service Manual for Joystick Assembly/ Disassembly.

3120728 – JLG Lift – 3-21

SECTION 3 - TROUBLESHOOTING

Will Only Drive A Short Distance

Overview Of Procedure

The following procedure will eliminate any problems found in the power circuit to the MC-1 controller box and also any
objectionable environmental conditions.

Check For These Obvious Conditions First:

• Is Battery Voltage 24 Volts? (Fully Charge Batteries)

Table 3-16. Only Drives A Short Distance

STEP ACTION SPEC YES NO

1. Is platform control ler staying powered up when ma chine stops driv­ing?

—Go to Step 2

2. Check the voltage out of the X101 connector, pin 5, to the power
relay pin 86. Check continuity at pin 85. 24 Volts Go to Step 3

3. Check the voltage from pin 87 on the power relay to the main con­tactor. (Main contactor should be closed at this point)

24 Volts Go to Step 4

4. Check the voltage on the Yel/Red, 2-5 wire on the X101 connector,
pin A1, from the main contactor. 24 Volts Go to Step 5

5. What type of surface is machine being operated on? Is surface soft,
unstable or up a steep grade?

Machine will not

perform well on a

soft or unstable

surface, if motor

—

draw is over 70

amps, controller

machine down.

6. Are brakes releasing when trying to drive?

—Go to Step 7

7. Is drive system running free? No noise or dragging.

—Go to Step 8

8. Is machine being operated in an environment with high static

Machine may be

charge?

charge in the MC-

—

which will make

the drive system

will shut the

( 7 LED Code)

building static

1 controller,

shut down.

Check the E-Stop

& Key Switch

Circuit

(Table 3-17)

Repai r or Repla ce
Wires, or Problem

with MC-1 Box

Repai r or Repla ce

Wires or Relay

Repai r or Repla ce

Wires or Main

Contactor

Go to Step 6

Repair/Replace

or Adjust Drive

Brakes

(See Procedure in

Service Manual)

Repair/Replace

or Adjust Drive

System

(See Procedure in

Service Manual)

—

3-22 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-17. E-Stop and Key Switch Circuit Check

• Batteries Fully Charged. (24 Volts)

• Ground Control Key Switch set to the Platform or on Ground position and the Emergency Stop Switch Reset to ON.

STEP ACTION SPEC YES NO

1. KEY SET TO PLATFORM: Check voltage on the Yel/Red, 2-2 wire
from the emergency stop switch to MC-1 controller box, pin 3 in the
X101 connector and pin 30 on the Power Relay.

2. KEY SET TO GROUND: Check voltage on the Yel/Red, 2-4 wire com-
ing out of the ground control box assembly to pin 87 on the power
relay, and main contactor. Yel/Red 2-8 wire to pin 86 on the ground
relay.

3. Open the Ground Control Box Assembly (housing with key switch
and E-stop switch mounted inside) and check the voltage on t he Yel/

Red, 2-1 wire leading into the emergency stop switch from the Key
switch.

4. Check voltage on the Red, 1-1 wire leading into the Key switch.

5. Check voltage and continuity through the 5 amp fuse mounte d inline

outside of the ground control box assembly, on the Red, 1-1 wire.

6. Check connection at batter y. 24 Volts Circuit OK N/A

24 Volts Circuit is OK Go to Step 2

24 Volts Circuit is OK Go to Step 3

Repair connec-

24 Volts

24 Volts

24 Volts Go to Step 6

tion to or replace

E-Stop switch

Repair connec-

tion to or replace

key switch

Go to Step 3

Go to Step 4

Replace Fuse or

Fuse Hol der if

damaged

3120728 – JLG Lift – 3-23

SECTION 3 - TROUBLESHOOTING

Won’t Drive Straight

Overview Of Procedure

The following procedure examines the drive motor assembly weldments attaching the drive motors to the base frame. Also
internal components of the the drive motors, gear box and a check of the components between the gear box and the drive
wheels.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Nothing is lodged between one of the wheels and the base frame.

• A caster wheel on the front of the machine is seized up, creating resistance.

• Joystick properly calibrated per procedure in Section-2 of Service Manual.

Table 3-18. Won’t Drive Straight.

STEP ACTION SPEC YES NO

1. Check for the following on the drive assembly, drive attachment
weldment; is bent, has broken welds, or loose hardware.

2. Check for the following on the drive assembly, drive motor mounting
plates; are bent, are square with drive weldments, or is hardware
loose?

3. Check for the following on the drive assembly, drive motor hard­ware; is hardware loose, flange bearing - bad/loose, slip clutch ­check torque settings or adjustment.

4. Check the left and right drive motor brakes for loose hardware & not
releasing properly.

5. Inside the drive motor gear box check if; the drive shaft is exces­sively loose & conditon of drive shaft bearings.
Are any gears broken or gear teeth excessively worn.

6. Is the electrical signal and amperage draw to the drive motors
equal?

7. Check the drive motor brushes, do they need replaced?

8. Is the X102 wiring harness (from platform contol box to MC-1 box)

damaged, check wiring harness visually and individual wires with
ohm meter.

9. Is joystick control defective?
If possible, swap out with another platform control.

10. Is MC-1 control box defective or connections not tight?
If possible, swap out with another MC-1 control box.

—

—

—

—

—

24 volts

15 amps

—

—

—

—

Repair/Replace/

Tighten weldment

Repair/Replace/

Tighten weldment

Repair/Replace/
Tighten compo-

nent

Tighten or Adjust

per procedure

in this

Service Manual

Repair/Replace
components per
procedure in this

Service Manual

Recheck Steps

1 thru 5

Replace per

procedure in this

Service Manual

Repair or Replace

Harness as

Required

Repair/Replace

Platform control

Tighten Connec-

tions or Replace

MC-1 box

Go to Step 2

Go to Step 3

Go to Step 4

Go to Step 5

Go to Step 6

Go to Step 7

Go to Step 8

Go to Step 9

Go to Step 10

—

3-24 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Noise From Drive Assembly

Overview Of Procedure

The following procedure examines the drive motor assembly weldments attaching the drive motors to the base frame. Also
internal components of the the drive motors, gear box and a check of the components between the gear box and the drive
wheels.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Nothing is lodged between one of the wheels and the base frame.

• A caster wheel on the front of the machine is seized up, creating resistance.

Table 3-19. Noise from Drive Assembly.

STEP ACTION SPEC YES NO

1. Check for the following on the drive assembly, drive attachment
weldment; is bent, has broken welds, or loose hardware.

2. Check for the following on the drive assembly, drive motor mounting
plates; are bent, are square with drive weldments, or is hardware
loose?

3. Check for the following on the drive assembly, drive motor hard­ware; is hardware loose, flange bearing - bad/loose, slip clutch ­check torque settings or adjustment.

4. Check the left and right drive motor brakes for loose hardware & not
releasing properly.

5. Inside the drive motor gear box check if; the drive shaft is exces­sively loose & conditon of drive shaft bearings.
Are any gears broken or gear teeth excessively worn.

6. Is the electrical signal and amperage draw to the drive motors
equal?

7. Check the drive motor brushes, do they need replaced?

—

—

—

—

—

24 volts

15 amps

—

Repair/Replace/

Tighten weldment

Repair/Replace/

Tighten weldment

Repair/Replace/

Tighten

Component

Tighten or Adjust

per procedure

in this

Service Manual
Repair/Replace

components per

procedure in this

Service Manual

Recheck Steps

1 thru 5

Replace per

procedure in this

Service Manual

Go to Step 2

Go to Step 3

Go to Step 4

Go to Step 5

Go to Step 6

Go to Step 7

—

3120728 – JLG Lift – 3-25

SECTION 3 - TROUBLESHOOTING

3.9 MAST TROUBLESHOOTING

Platform Will Not Lift Up Using Platform Control

Overview Of Procedure

This procedure examines the complete pump motor, ground control and pump valves electrical circuits.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Platform loaded within maximum allowable capacity.

• Hydraulic oil is within it’s specified operating temperature range.

Table 3-20. Platform Will Not Lift Up Using Platform Control.

STEP ACTION SPEC YES NO

1. Will platform lift from ground control switch?
Note: Key switch must be set to GRND to test this.

2. Does pump motor run?

3. Are the down and dump valves opening/closing properly?

Note: If machine will not lift and hydraulic oil is visible flowing in the
hydraulic tank, the dump valve is stuck in the open position.

4. Is the pressure set properly on the pump?

5. Is the lift cyl inder OK?

6. Are the mast sections operating freely?

— Go to Step 2 See (Figure 3-24)

See Pump Circuit

—Go to Step 3

(Table 3-21 )

See Pump Valves

—Go to Step 4

Circuit Check
(Table 3-22 )

Set to correct

—Go to Step 5

pressure specifi-

cation per this

Service Manual

—Go to Step 6

—

Consult

Factory

Replace Lift Cyl.

Check

Rebuild or

Check Mast,

Rebuild

if Necessary

3-26 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Table 3-21. Pump Circuit

• Battery voltage 24 volts. (Fully charge batteries)

• Key switch set to Platform .

STEP ACTION SPEC YES NO

1. At the pump motor, check for 24 volts at both ends of the batter y
cable running from the main contactor to the pump case stud. (left
side)

PUMP CONTACTOR RELAY CIRCUIT

2. Check the connection of the ground cable (attached to 5/16" stud,
left side) to t he pump contactor, is t ight and connecte d on other end
to B- at the right side battery.

3. Check the connection of the ground cable (other side) is tight and
connected to the pump case stud (center).

4. Check the Yel/Red, 2-6 wire connected to the positive post on the
pump case for tightness and 24 volt reading.

5. Check the Tan, 55-1 wire connected to both the Ground control
switch and the MC-1 box, X105 connector, pin 5 through the pump
contactor relay. Without any lift functions activated, it should show
24 volts, with a lift function activated it should show ground.

DUMP VALVE CIRCUIT

6. Check the Yel/Red, 2-6 wire connected to the positive (+) post on
the pump case for 24 volts.

7. Check the Tan, 3-1 wire connected to both the Ground control
switch and the MC-1 box, X105 connector, pin 4 through the lif t up
valve. Without any lift function activated, it should show 24 volts,
with a lift function activated it should show ground.

DOWN VALVE CIRCUIT

8. Check the Yel/Red, 2-6 wire connected to the positive (+) post on
the pump case for 24 volts.

9. Check the Tan, 4-1 wire connected to both the Ground control
switch and the MC-1 box, X105 connector, pin 6 through the lif t
down valve. Without any lift functions, it should show 24 volts, with
a lift function it should show ground.

MAIN CONTACTOR CIRCUIT

10. Check the battery cable from the B+ (left side) battery for 24 volts.

11. Check the battery cable going out to the pump case (left side) stud

for 24 volts.

12. Check the Yel/Red, 2-5 (10 ga.) wire to the MC -1 box, X101 connec­tor, pin A1 for 24 volts.

13. Check the Yel/Red, 2-4 wire to the Power Relay, pin #87 for 24
volts.

2 4 v ol ts G o t o S te p 2

Ground Go to Step 3

Ground Go to Step 4

2 4 v ol ts G o t o S te p 5

Ground Go to Step 6

2 4 v ol ts G o t o S te p 7

2 4 v ol ts G o t o S te p 8

2 4 v ol ts G o t o S te p 9

24 volts Go to Step 10

24 volts Go to Step 11

24 volts Go to Step 12

24 volts Go to Step 13

24 volts Go to Step 14

Connection or
Replace Cable

if Necessary

Connection or
Replace Cable

if Necessary

Connection or
Replace Cable

if Necessary

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten

Tighten

Tighten

3120728 – JLG Lift – 3-27

SECTION 3 - TROUBLESHOOTING

Table 3-21. Pump Circuit

14. Check the Black to ground on the pump contactor.

POWER RELAY CIRCUIT

15. Check the Yel/Red, 2-4 wire, #87 on the Power Relay to the main
contactor, and to diode at E-Stop for 24 volts.
N ot e: Po w er w i ll s to p a t d io de , s il v e r l i ne s ho u ld be a w ay f r om t he E­Stop.

16. Check the Yel/Red, 2-2 wire, #30 on the Power Relay to the E-stop
and to the MC -1 box, X101 connector pin 3, for 24 volts.

17. Check the Black, #85 pin on the Power Relay for connection to
ground at pump contactor.

18. Check the Yel/Red, 2-3 wire, #86 on the Power Relay to the MC-1
box, X101 connector pin 5, for 24 volts when the platform control is
powered up.

Table 3-22. Pump Valves Circuit

• Battery voltage 24 volts. (Fully charge batteries)

• Set key switch to Platform and set the Emergency Stop Button to the RESET position.

• Down Valve should be normal (closed).

• Dump Valve (up) should be normal (open).

• If machine will not lift and hydraulic oil is visible flowing in the hydraulic tank, the dump valve is stuck open.

Ground Go to Step 15

24 volts Go to Step 16

24 volts Go to Step 17

Ground Go to Step

—Go to Step

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

Tighten/Repair

Connection

STEP ACTION SPEC YES NO

LIFT UP - (CONDITIONS WHEN PUMP MOTOR IS RUNNING)

1. Pump Contactor Coil: Yel/Red, 2-6 wire - 24 volts
Tan, 55-1 wire - Ground

2. Lift Up Valve Coil: Yel/Red, 2-6 wire - 24 volts

Tan, 3-1 wire - Ground

LIFT UP - (CHECK WHEN PUMP MOTOR IS NOT RUNNING)

3. Pump Contactor Coil: Yel/Red, 2-6 wire - 24 volts
Tan, 55-1 wire - 24 volts

4. Lift Up Valve Coil: Yel/Red, 2-6 wire - 24 volts

Tan, 3-1 wire - 24 volts

LIFT DOWN - (CHECK WHEN DOWN AND ENABLE PADS ARE PUSHED ON THE PLATFORM CONTROL)

5. Lift Down Valve Coil:Yel/Red, 2-6 wire - 24 volts

Tan, 4-1 wire - Ground

LIFT DOWN - (CHECK WHEN NO FUNCTION ARE ENABLED ON THE PLATFORM CONTROL)

6. Lift Down Valve Coil:Yel/Red, 2-6 wire - 24 volts

Tan, 4-1 wire - 24 volts

———

———

———

———

———

———

3-28 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Platform Will Not Lower Using Platform Control

Overview Of Procedure

This procedure tests for ground coming out of the MC-1 box to the dump valve circuit and through to the ground control tog­gle switch.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Hydraulic oil is within it’s specified operating temperature range.

Table 3-23. Platform Will Not Lower Using Platform Control.

STEP ACTION SPEC YES NO

1. Will machine lower manually, using the manual descent knob? — Go to Step 2 See (Table 3-26)

2. Will machine lower from ground control switch?

Note: Key switch must be set to GRND to check this.

3. Check for ground on the Tan, 4-1 wire at the MC-1 box, X105 con­nector, pin 6.

4. Check for ground on the Tan, 4-1 wire at the lift down coil.

5. Check complete pump motor circuit . (See Table 3-21) — — —

— Go to Step 3 See (Table 3-23)

Repair/Replace

—Go to Step 4

Joystick/

MC-1 Box

Replace/Repair

—Go to Step 5

Wire or

Connection

3120728 – JLG Lift – 3-29

SECTION 3 - TROUBLESHOOTING

Platform Will Not Lift Up From Ground Control Toggle Switch

Overview Of Procedure

The following procedure examines the complete ground control circuit from the battery all the way to the pump motor for
wiring or components which could be causing a failure of that circuit.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Battery connections clean and tight.

• Key switch positioned to Ground (GRND) control.

• Emergency stop switch pulled out. (Reset Position)

• Ground control power supply and wiring, OK (Table 3-4).

• Manual descent valve closed.

• 5 amp fuses on power and pump circuits, OK.

• Hydraulic oil level, OK.

• Weight in platform does not exceed machine maximum capacity.

Table 3-24. Unit Will Not Lift Up From Ground Control Toggle Switch.

STEP ACTION SPEC YES NO

1. Does the pump motor r un when lift up is selected at the ground con­trol switch?

Note: Steps 2 thru 9 are to be performed with LIFT UP selected at the
ground control.

2. Check terminal 30 and 85 on the ground control relay for ground. Is
ground contact OK?

3. Check continuity across terminals 87 and 30 on the ground control
relay. Is there continuity? (Relay must be energized)

4. Check the Black wire from terminal 87 on the ground control relay to
the lift up/down ground control switch. Is there continuity with B –?

5. Check for continuity across the ter minals (Black to Tan 3-1 and Tan
55-1) of the lift up/down ground control toggle switch. Is there con­tinuity?

6. Check the Tan, 3-1 wire for continuity from the lif t up/down ground
switch to the lift up coil. Is there continuity?

7. Check the Tan, 55-1 wire from the lift up/down ground switch to the
pump contactor for continuity. Is there continuity?

8. Check the Yel/Red, 2-6 wire from the pump motor to the pump con­tactor and lift-up coil for voltage. Is there voltage?

9. Check the wire from the lift switch (Tan 55-1) pump contactor to the
battery (-) terminal for continuity. Is there continuity?

10. Check the pump motor pressure relief setting. Is it within specifica­tion per Service Manual?

—

Go to Steps 5,6

and 10

Ground Go to Step 3

— Go to Step 4 Replace Relay

—Go to Step 5

—Go to Step 6

—Go to Step 7

—Go to Step 8

24 Volts Go to Step 9

——

— Set as Required

Check Ground

Power Circuit

(Table 3-4)

Before Continu-

ing to Step 3

Repair Wiring or

Connection

Repair Wiring or

Connection

Replace Lift Up/

Down Ground

Control Switch

Repair Wiring or

Connection

Repair Wiring or

Connection

Repair Wiring or

Connection

Repair Wiring or

Connection

3-30 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Platform Will Not Lower From Ground Control Toggle Switch

Overview Of Procedure

The following procedure examines the complete ground control circuit from the battery all the way to the pump motor for
wiring or components which could be causing a failure of that circuit.

Check For These Obvious Conditions First:

• Battery voltage 24 volts. (Fully charge batteries)

• Battery connections clean and tight.

• Key switch positioned to Ground (GRND) control.

• Emergency stop switch set to the Reset position)

• Ground control power supply and wiring, OK (Table 3-4).

• 5 amp fuses on power and pump circuits, OK.

• Hydraulic oil level, OK.

Table 3-25. Unit Will Not Lower From Ground Control Toggle Switch.

STEP ACTION SPEC YES NO

1. Will machine lower manually? — Go to Step 3 Go to Step 2

2. Check for obstructions in the mast, cylinder, hydraulic lines and lift

down valve.

3. Check terminal 30 and 85 on the ground control relay for ground. Is
ground contact OK? Continuity with B–.

4. Check continuity across terminals 87 and 30 on the ground control
relay. Is there continuity? (Relay must be energized)

5. Check the Black wire from terminal 87 on the ground control relay to
the lift up/down ground control switch. Is there continuity with B –?

6. Check for continuity across the ter minals (Black to Tan, 4-1 wire) of
the lift up/down ground control toggle switch. Is there continuity
with the switch activated?

7. Check the Tan, 4-1 wire for continuity from the lif t up/down ground
switch to the lift-down coil. Is there continuity?

8. Check the Yel/Red, 2-6 wire from the pump motor to the lift-down
coil for voltage. Is there voltage?

—

Ground Go to Step 4

Ground Go to Step 5 Replace Relay

—Go to Step 6

—Go to Step 7

—Go to Step 7

24 volts —

Repair, Replace

or Adjust

Go to Step 3

Repair Wiring or

Connection

Repair Wiring or

Connection

Replace Lift Up/

Down Ground

Control Switch

Repair Wiring or

Connection

Repair Wiring or

Connection

3120728 – JLG Lift – 3-31

SECTION 3 - TROUBLESHOOTING

Platform Will Not Lower Manually

Overview Of Procedure

The following procedure suggests components on the machine which might attribute to problems with the manual descent
circuit.

Table 3-26. Platform Will Not Lower Manually.

STEP ACTION SPEC YES NO

1. Check manual override solenoid with manua l override (knob open). Go to Step 2 Open

2. Check Steps 1 thru 6 of ( Table 3-30) Repair Go to Step 3

3. Place the maximum capacity of weight in the Platform.

Does it Lower?

— Consult Factory

3-32 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Platform Lift Up And Down Jerky

Overview Of Procedure

The following procedure suggests areas on the machine which might attribute to erratic movement of the platform during lift
up and down.

Check For These Obvious Conditions First:

• If mast is not running smooth or has tight and rough spots, refer to the Mast Section Rebuild.

• Hydraulic oil level in reservoir tank at full level.

• Hydraulic oil no milky (presence of water), or not foamy (full of air).

Table 3-27. Platform Lift Up and Down Jerky.

STEP ACTION SPEC YES NO

CONTROLS (ELECTRICAL)

1. Is platform control, enable, up or down pad defective or worn out? — Replace pad Go to Step 2

2. Loose connections , ground and power.

—

3. Valve coils or solenoids keep opening and closing.

—

4. Problem internal to the MC-1 co ntrol box. — Replace box Go to Step 5

HYDRAULIC

5. Are the hydraulic valves working properly. — Replace Valve Go to Step 6

6. Pump drive cavitates. — Replace Pump Go to Step 7

7. Lift cylinder

—

Repair

connection

Repair Connec-

tion or Replace

Val ve

Rebuild or

Replace Cylinder

Go to Step 3

Go to Step 4

—

3120728 – JLG Lift – 3-33

SECTION 3 - TROUBLESHOOTING

Mast Noisy When Lifting And Lowering

Overview Of Procedure

This procedure examines components of the mast itself and as well as it’s lifting components for dirt, debris, proper lubrica­tion and operation.

STEP ACTION SPEC YES NO

1. Do slide pads and slide pad channels need to be cleaned of dust,
dirt, or other debris?

2. Do chain/cables need to be lubricated per JLG specification in the
Service Manual?

3. Are the chain/cable sheave wheels dry and need lubrication?
Note: Plastic wheels will howl on the sheave pin when they are dry.
Sheave wheels may seize to the sheave pin and the pin may turn in
the pin retainer blocks.

Table 3-28. Mast Noisy when Lifting and Lowering.

—

—

—

Clean Pads and

Channels

Lubricate as

Required

Lubricate or

Replace Sheave

Pins and Wheels

4. Are the sequence cables (located on the side of mast) chattering
when the springs are compressed?
Note: This noise is normal at the sequence cable sheave wheels
when the mast is completely lowered. However if the sequence
cable chattering is happeni ng no matter what position the mast is in,
it could be a result of the mast being shimmed to tight or dir t and

—

Clean Slide Pads/

Channels or Re-

shim Mast per

Service Manual

debris in the slide pad channels causing the mast to be tight.

5. Is the bore of the lif t cylinder dry?

6. Are the bearings in the lift pump motor and pump drive worn?

7. Are the hydraulic lines vibrating together?

8. Check if the pump motor is loose to it’s mounting plate.

—

—

—

—

Replace Packing

or Lift Cylinder

Repair or Replace

Pump

Adjust the Posi­tion of the Lines

Tighten pump

mounting
fasteners

9. Hydraulic oil could be cavatating inside the pump.

—

Repair or Replace

Pump

Go to Step 2

Go to Step 3

Go to Step 4

Go to Step 5

Go to Step 6

Go to Step 7

Go to Step 8

Go to Step 9

—

3-34 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

Platform (Mast) Won’t Stay Elevated

Overview Of Procedure

The following procedure requests that the lift down, dump, and pump internal valves be checked to see if any are stuck
open, it also examines the lift down and dump valve circuits. Also suggests that the lift cylinder packing could be leaking
internally.

Check For These Obvious Conditions First:

• Manual descent valve is closed tight.

Table 3-29. Platform (Mast) Won’t Stay Elevated.

STEP ACTION SPEC YES NO

1. Is the lift down valve stuck open?

—

2. Check the valve inside the pump, it could be stuck open. — Replace Pump Go to Step 3

3. Lift down valves could be open due to incorrect electrical signal.

—

4. Dump valve could be open due to incorrect electrical signal.
—

5. Oil could be passing around the lift cylinder bore packing.
—

Repair or Clean

Val ve

Check Pump

Valve Electrical

Circuit

(Table 3-22)

Check Pump

Valve Electrical

Circuit

(Table 3-22)

Replace or

Rebuild the Lift

Cylinder

Go to Step 2

Go to Step 4

Go to Step 5

—

3120728 – JLG Lift – 3-35

SECTION 3 - TROUBLESHOOTING

Platform (Mast) Descends Too Slowly

Overview Of Procedure

The following procedure examines the mast some hydraulic components for obstructions and defects.

Table 3-30. Platform (Mast) Descends Too Slowly.

STEP ACTION SPEC YES NO

1. Check mast slide pads shimmed to tight. — Reshim Mast Go to Step 2

2. Is there an obstruction in the mast?

3. The lift cylinder packing could be too tight in the bore of the cylinder

barrel.

4. Check the flow valve on the extend hydraulic line for a restriction, i.e.
dirt.

5. Check if the lift down valve is opening completely.

6. Is there a restricted hydraulic line (smashed)?

—

—

—

—

—

Remove

Obstruction

Rebuild or

Replace Cylinder
Clean or Replace

Flow Valve

Clean or Replace

Val ve

Replace Hydrau-

lic Line

Go to Step 3

Go to Step 4

Go to Step 5

Go to Step 6

—

3-36 – JLG Lift – 3120728

SECTION 3 - TROUBLESHOOTING

3.10 HYDRAULIC LEAK TROUBLESHOOTING

Miscellaneous Hydraulic Leak Troubleshooting

Overview Of Procedure

This series of steps gives remedies for various areas of the machine where leaks could occur.

STEP ACTION SPEC YES NO

1. Oil leaking around the lif t cylinder rod.

Table 3-31. Hydraulic Leak Troubleshooting

—

Replace the Seal

at the end of the

Piston and

Cylinder Barrel

2. Oil leaking around the cylinder fitting/flow valve.

3. Oil leaking around the hydraulic lines.

—

—

Tighten or

Replace Fittings

Tighten or

Replace

Hydraulic Lines

4. Oil leaking around the lif t up valve.

5. Oil leaking around the lift down valve.

6. Oil leaking around the (Red) manual descent valve.

Note: Do not overtighten the nut on the solenoid in steps 4, 5, and 6.

—

—

—

Tight Cartridge in

Pump Case

Tighten Cartridge

in Pump Case

Replace Lift
Down Valve

—

—

—

—

—

—

3120728 – JLG Lift – 3-37

SECTION 3 - TROUBLESHOOTING

3.11 BASE FRAME COMPONENTS TROUBLESHOOTING

Caster Wheels Not Operating Freely

Check For These Obvious Conditions First:

• Is machine operating on a smooth, level surface?

Table 3-32. Caster Wheels Not Operating Freely.

STEP ACTION SPEC YES NO

1. Is the caster rotating freely?

2. Is the wheel spinning freely?

3. Is debris stuck in the plastic wheel?

—Go to Step 2

— Go toStep 3

—

Remove Debris or

Replace Wheel

Replace Caster

Replace Wheel

Lubricate or

Housing

Lubricate or

—

Pot Hole Protection (PHP) Bars Will Not Set

Check For These Obvious Conditions First:

• Obstruction under pot hole bar on either side of machine.

• Obstruction around the actuator assembly at the base of the mast.

Table 3-33. Pot Hole Protection (PHP) Bars Will Not Set.

STEP ACTION SPEC YES NO

1. Check the actuator cables for adjustment or damage. — Adjust or Replace Go to Step 2

2. Check the PHP limit switch(s) at both sides of the machine for dam-

age, adjustment and for continuity through switch to ground when
bars are down.

—

Replace, Adjust

or Repair Wiring

—

3-38 – JLG Lift – 3120728

McConnellsburg PA. 17233-9533

Customer Support Toll Free: [phone]

JLG Worldwide Locations

Corporate Office

JLG Industries, Inc.

1 JLG Drive

USA

Phone: [phone]

Fax: [phone]

JLG Industries (Australia)
P.O. Box 5119
11 Bolwarra Road
Port Macquarie
N.S.W. 2444
Australia
Phone: [phone]
Fax: [phone]

JLG Latino Americana Ltda.
Rua Eng. Carlos Stevenson,
80-Suite 71
13092-310 Campinas-SP
Brazil
Phone: [phone]
Fax: [phone]

JLG Industries (Europe)
Kilmartin Place,
Tannochside Park
Uddingston G71 5PH
Scotland
Phone: [phone]
Fax: [phone]

JLG Industries (UK)
Unit 12, Southside
Bredbury Park Industrial Estate
Bredbury
Stockport
SK6 2sP
England
Phone: [phone]
Fax: [phone]

JLG Europe B.V.
Jupiterstraat 234
2132 HJ Foofddorp
The Netherlands
Phone: [phone]
Fax: [phone]

JLG Industries (Pty) Ltd.
Unit 1, 24 Industrial Complex
Herman Street
Meadowdale
Germiston
South Africa
Phone: [phone]
Fax: [phone]

JLG Deutschland GmbH
Max Planck Strasse 21
D-27721 Ritterhude/lhlpohl
Bei Bremen
Germany
Phone: [phone]
Fax: [phone]

JLG Industries (Norge AS)
Sofeimyrveien 12
N-1412 Sofienyr
Norway
Phone: [phone]
Fax: [phone]

Plataformas Elevadoras
JLG Iberica, S.L.
Trapadella, 2
P.I. Castellbisbal Sur
08755Castellbisbal
Spain
Phone: [phone]
Fax: [phone]

JLG Industries (Italia)
Via Po. 22
20010 Pregnana Milanese - MI
Italy
Phone: [phone]
Fax: [phone]

JLG Polska
UI. Krolewska
00-060 Warsawa
Pol an d
Phone: [phone]
Fax: [phone]

JLG Industries (Sweden)
Enkopingsvagen 150
Box 704
SE - 175 27 Jarfalla
Sweden
Phone: [phone]
Fax: [phone]