Service 3120819 05-16

Service and Maintenance Manual
Model
120HX
3120819
May 16, 2002
INTRODUCTION
SECTION A. INTRODUCTION - MAINTENANCE SAFETY
PRECAUTIONS
A
feed lines to system components can then be disconnected
with minimal fluid loss.
GENERAL
This section contains the general safety precautions which
must be observed during maintenance of the aerial platform. It is of utmost importance that maintenance personnel pay strict attention to these warnings and precautions
to avoid possible injury to themselves or others, or damage to the equipment. A maintenance program must be
followed to ensure that the machine is safe to operate.
MODIFICATION OF THE MACHINE WITHOUT CERTIFICATION BY
A RESPONSIBLE AUTHORITY THAT THE MACHINE IS AT LEAST
AS SAFE AS ORIGINALLY MANUFACTURED, IS A SAFETY VIOLATION.
The specific precautions to be observed during maintenance are inserted at the appropriate point in the manual.
These precautions are, for the most part, those that apply
when servicing hydraulic and larger machine component
parts.
Your safety, and that of others, is the first consideration
when engaging in the maintenance of equipment. Always
be conscious of weight. Never attempt to move heavy
parts without the aid of a mechanical device. Do not allow
heavy objects to rest in an unstable position. When raising
a portion of the equipment, ensure that adequate support is
provided.
SINCE THE MACHINE MANUFACTURER HAS NO DIRECT CONTROL OVER THE FIELD INSPECTION AND MAINTENANCE,
SAFETY IN THIS AREA RESPONSIBILITY OF THE OWNER/OPERATOR.
B
HYDRAULIC SYSTEM SAFETY
It should be noted that the machines hydraulic systems
operate at extremely high potentially dangerous pressures.
Every effort should be made to relieve any system pressure prior to disconnecting or removing any portion of the
system.
C
MAINTENANCE
FAILURE TO COMPLY WITH SAFETY PRECAUTIONS LISTED IN
THIS SECTION MAY RESULT IN MACHINE DAMAGE, PERSONNEL
INJURY OR DEATH AND IS A SAFETY VIOLATION.
• NO SMOKING IS MANDATORY. NEVER REFUEL DURING ELECTRICAL STORMS. ENSURE THAT FUEL
CAP IS CLOSED AND SECURE AT ALL OTHER
TIMES.
• REMOVE ALL RINGS, WATCHES AND JEWELRY
WHEN PERFORMING ANY MAINTENANCE.
• DO NOT WEAR LONG HAIR UNRESTRAINED, OR
LOOSE-FITTING CLOTHING AND NECKTIES WHICH
ARE APT TO BECOME CAUGHT ON OR ENTANGLED
IN EQUIPMENT.
• OBSERVE AND OBEY ALL WARNINGS AND CAUTIONS ON MACHINE AND IN SERVICEMANUAL.
• KEEP OIL, GREASE, WATER, ETC. WIPED FROM
STANDING SURFACES AND HAND HOLDS.
• USE CAUTION WHEN CHECKING A HOT, PRESSURIZED COOLANT SYSTEM.
• NEVER WORK UNDER AN ELEVATED BOOM UNTIL
BOOM HAS BEEN SAFELY RESTRAINED FROM ANY
MOVEMENT BY BLOCKING OR OVERHEAD SLING,
OR BOOM SAFETY PROP HAS BEEN ENGAGED.
• BEFORE MAKING ADJUSTMENTS, LUBRICATING OR
PERFORMING ANY OTHER MAINTENANCE, SHUT
OFF ALL POWER CONTROLS.
• BATTERY SHOULD ALWAYS BE DISCONNECTEDDURING REPLACEMENT OF ELECTRICAL COMPONENTS.
• KEEP ALL SUPPORT EQUIPMENT AND ATTACHMENTS STOWED IN THEIR PROPER PLACE.
• USE ONLY APPROVED, NONFLAMMABLE CLEANING
SOLVENTS.
Relieve system pressure by cycling the applicable control
several times with the engine stopped and ignition on, to
direct any line pressure back into the reservoir. Pressure
3120819
– JLG Lift –
A-1
INTRODUCTION
REVISON LOG
March 31, 1992
January 1, 1996
January, 1999
August 9, 2001
May 16, 2002
A-2
- Original Issue
- Revised
- Revised
- Revised
- Revised
– JLG Lift –
3120819
TABLE OF CONTENTS
TABLE OF CONTENTS
SUBJECT - SECTION, PARAGRAPH
PAGE NO.
SECTION A - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS
A
B
C
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
Hydraulic System Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
SECTION 1 - SPECIFICATIONS
1.1
1.2
1.3
1.4
1.5
1.6
1.7
3120819
Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Hydraulic Oil Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Hydraulic System (Including Tank) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Engine Crankcase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Diesel Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Drive/Steer System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Swing System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Function Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Drive Hydraulic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Auxiliary Power Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Hydraulic Filter - Inline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Travel Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Gradeability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Turning Radius (4 Wheel Steer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Platform Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Boom Elevation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Machine Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Maximum Tire Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Machine Height (Stowed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Machine Length (Stowed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Machine Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Wheelbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Function Speeds (Machines Built Prior to S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Telescope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Extend-A-Reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Swing Speed 360° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Platform Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Ground to 120’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
From 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Ground to 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Function Speeds (Machines Built After S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Telescope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Extend-A-Reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Swing Speed 360° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Platform Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Ground to 120’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
From 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Ground to 120’ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Engine (Crankcase) Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
– JLG Lift –
i
TABLE OF CONTENTS (Continued)
TABLE OF CONTENTS (continued)
SUBJECT - SECTION, PARAGRAPH
1.8
1.9
1.10
1.11
1.12
1.13
PAGE NO.
Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Pressure Settings - PSI (Bar) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10
Main Control Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Frame Mounted Control Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11
Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11
Boom Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
Standard Boom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
w/Boom Wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
SECTION 2 - PROCEDURES
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
ii
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
Servicing and Maintenance Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Safety and Workmanship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Cleanliness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Components Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Component Disassembly and Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Pressure-Fit Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Bolt Usage and Torque Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Hydraulic Lines and Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Hydraulic System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Lubrication and Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Lubrication Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Hydraulic System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Changing Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Cylinders - Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Valves - Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Solenoid Control Valves (Bang-Bang) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Manual Hydraulic Control Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Relief Valves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Crossover Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Boom Chains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Adjusting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Inspection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Wear Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Drift Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Telescope Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Lift Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Cylinder Checking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9
Cylinder w/o Counterbalance Valves - Steer Cylinders, Master Level Cylinder,
Frame Jack Cylinders.
2-9
Cylinders w/Single Counterbalance Valves - Lift Cylinder, Telescope Cylinder,
Extend-A-Reach Cylinder.
2-10
Cylinders w/Dual Counterbalance Valve - Axle Extension Cylinders, Telescope Cylinder,
Platform Slave Level Cylinder
2-10
– JLG Lift –
3120819
TABLE OF CONTENTS
TABLE OF CONTENTS (continued)
SUBJECT - SECTION, PARAGRAPH
2.10
2.11
2.12
2.13
2.14
2.15
2.16
2.17
2.18
2.19
2.20
2.21
2.22
2.23
3120819
PAGE NO.
Cylinder Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11
Telescope Cylinder Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Telescope Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Lift Cylinder Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Lift Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Master Level Cylinder Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Master Level Cylinder Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Boom Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-17
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23
Tilt Alarm Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24
Manual Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
Voltmeter Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Limit Switch Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25
Boom Limit Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Horizontal Cut-Out Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Throttle Checks and Adjustments - Deutz Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25
Pressure Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25
Main Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Frame Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Swing Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32
Turntable Bearing Mounting Bolt Condition Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32
Wear Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Swing Bearing Torque Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Drive Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
Swing Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-40
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
swing brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-43
Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Drive Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-45
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Free Wheeling Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-47
To Disengage Drive Motors and Brakes (Free Wheel) for Towing, etc . . . . . . . . . . . . . . . . 2-47
To Engage Drive Motors and Brakes (Normal Operation) . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47
PQ Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48
TRIM Adjustment (Prior to S/N 38697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48
TRIM Adjustment (S/N 38697 to Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-49
RAMP Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-50
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TABLE OF CONTENTS (Continued)
TABLE OF CONTENTS (continued)
SUBJECT - SECTION, PARAGRAPH
2.24
2.25
2.26
2.27
2.28
2.29
2.30
PAGE NO.
Boom Marking Tape Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-51
Boom Length/Angle Sensor Adjusting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-51
Length Indicator Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52
Boom Angle Sensor Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52
Radius Adjustment and Display Lights Setting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52
Operational Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53
Lift Down Speed Limit Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53
Load Management System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-53
Platform Position Indication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-53
Overmoment Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-54
Overmoment Control Monitoring System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55
Load Management System Daily Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-55
Load Management System Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58
Turntable Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-58
Drive Motor Adjustment Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-58
Preventive Maintenance and Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-60
SECTION 3 - TROUBLESHOOTING
3.1
3.2
3.3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Hydraulic Circuit Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
LIST OF FIGURES
FIGURE NO.
1-1.
1-2.
1-3.
2-1.
2-2.
2-3.
2-4.
2-5.
2-6.
2-7.
2-8.
2-9.
2-10.
2-11.
2-12.
2-13.
2-14.
2-15.
2-16.
2-17.
2-18.
2-19.
2-20.
2-21.
2-22.
2-23.
2-24.
iv
TITLE
PAGE NO.
Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7
Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11
Boom Chain Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Typical Boom Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
Cylinder Barrel Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
Cylinder Rod Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
Poly-Pak Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15
Boom Assembly - Sheet 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Boom Assembly - Sheet 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-19
Tilt Switch Adjustment - Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24
Tilt Switch Adjustment - Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24
Throttle Checks and Adjustments - Deutz Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-26
Pressure Setting Adjustments - Main Valve - Machines Built Before S/N 38697 . . . . . . . . . . . . .2-28
Pressure Setting Adjustments - Frame Valve - Machines Built Before S/N 38697 . . . . . . . . . . . .2-29
Pressure Setting Adjustments - Main Valve - Machines Built After S/N 38697 . . . . . . . . . . . . . . .2-30
Pressure Setting Adjustments - Frame Valve - Machines Built After S/N 38697 . . . . . . . . . . . . . .2-31
Swing Bearing Bolt Feeler Gauge Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32
Swing Bearing Tolerance Boom Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-33
Swing Bearing Tolerance Measuring Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-34
Swing Bearing Bolt Torquing Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-35
Drive Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-36
Swing Torque Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-41
Swing Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-44
Drive Brake, Mico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-46
Spring Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-47
Boom Marking Tape Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-51
– JLG Lift –
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TABLE OF CONTENTS
LIST OF FIGURES (continued)
FIGURE NO.
2-25.
2-26.
2-27.
2-28.
2-29.
3-1.
3-2.
3-3.
3-4.
3-5.
3-6.
3-7.
TITLE
PAGE NO.
Control Box Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-54
Boom Length/Angle Sensor Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-56
Load Moment Limiting System Monitoring Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-57
Load Radius Circuit Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-59
Drive Motor Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-60
Electrical Diagram - Boom Length Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21
Electrical Schematic - CE - Sheet 1 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22
Electrical Schematic - CE - Sheet 2 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-23
Electrical Schematic - CE - Sheet 3 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24
Electrical Schematic - CE - Sheet 4 of 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25
Hydraulic Schematic - (Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-26
Hydraulic Schematic - (Sheet 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27
LIST OF TABLES
TABLE NO.
1-1
1-2
1-3
1-4
1-5
1-6
1-7
1-8
1-9
2-1
2-2
2-3
2-4
2-5
2-6
2-7
3-1
3-2
3-3
3-4
3-5
3-6
3120819
TITLE
PAGE NO.
Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Single Viscosity Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Multi Viscosity Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Lubrication Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11
Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12
Chain Stretch Tolerance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Cylinder Piston Nut Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16
Holding Valve Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16
Function Speeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48
Platform Controller Settings (Prior to S/N 38697). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48
Platform Controller Settings (S/N 38697 to Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48
Preventive Maintenance and Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-61
Platform Assembly - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Boom Assembly - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Turntable Assembly - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Chassis Assembly - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Hydraulic System - Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14
Electrical System - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17
– JLG Lift –
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TABLE OF CONTENTS (Continued)
This page left blank intentionally.
vi
– JLG Lift –
3120819
SECTION 1 - SPECIFICATIONS
SECTION 1. SPECIFICATIONS
1.1
Swing System
CAPACITIES
Swing Motor Displacement - 32.8 cm[3]/rev. (2.0 in.[3]/
rev.).
Fuel Tank
Hydraulic Oil Tank
Swing Brake - Automatic spring applied, hydraulically
released. Release pressure 10.5 kg/cm[2] (150 psi) initial,
12.0 kg/cm[2] (170 psi) full.
189 liters (50 gallons).
Function Hydraulic Pump
Hydraulic System (Including Tank)
Vendor - John Barnes.
Approximately 60 gallons (227 liters).
Single section gear pump - 1589 cm[3] (97 in.[3]) displacement.
Torque Hub
Output - 28.4 lpm (7.5 gpm) @ 1800 rpm; 39.7 lpm (10.5
gpm) @ 2500 rpm.
98 liters (26 gallons).
Drive - 2.7 liters (2.9 quarts).
Drive Hydraulic Pump
Swing - 1.3 liters (1.4 quarts).
Vendor - Sunstrand.
NOTE: Torque hubs should be one half full of lubricant.
Engine Crankcase
Overcenter piston pump - 45.9 cm[3] (2.8 in.[3]) displacement.
9.5 liters (10.0 quarts) w/o filter.
Output - 113.5 lpm (30 gpm) @ 2500 rpm.
1.2
Auxiliary Power Pump
COMPONENT DATA
Vendor - John Barnes.
Diesel Engine
Single section gear pump.
Manufacturer/Model - Deutz F4L912.
Displacement - 2.1 cm[3] (0.2 in.[3])/rev.
Oil Capacity - 9.5 liters (10.0 quarts) w/o filter.
Output - 18 lpm (4.8 gpm).
Low RPM - 1800.
Hydraulic Filter - Inline
High RPM - 2500.
Return - Bypass Type.
Alternator - 60 Amp, belt drive.
25 Microns Nominal.
Battery - 85 Amphour, 550 Cold Cranking Amps, 12 VDC.
Horsepower - 76 @ 2500 RPM, no load.
1.3
PERFORMANCE DATA
Drive/Steer System
Travel Speed
Tires - 445/65R22.5, foam filled.
2WD - 5.1 km/hr (3.2 mph).
Drive Hub - 93.7:1 ratio.
4WD - 4.3 km/hr (2.7 mph).
Drive Brake - Spring applied, hydraulically released,
release pressure 9.7 bar (140 psi).
Gradeability
Drive Motor - 2 speed, 6.4 cm[3]/rev. (0.4 in.[3]/rev.) low
speed, 2.5 cm[3]/rev. (0.2 in.[3]/rev.) high speed.
3120819
2WD - 25%.
4WD - 40%.
– JLG Lift –
1-1
SECTION 1 - SPECIFICATIONS
Turning Radius (4 Wheel Steer)
1.4
Outside.
5.86 m (19 ft. 3 in.) w/axles extended.
5.48 m (18 ft. 0 in.) w/axles retracted.
Inside.
FUNCTION SPEEDS (MACHINES BUILT
PRIOR TO S/N 38697)
Telescope
Extend - 132-170 seconds.
Retract - 140-175 seconds.
2.59 m (8 ft. 6 in.) w/axles extended.
2.79 m (9 ft. 2 in.) w/axles retracted.
Lift
Up - 125-160 seconds.
Platform Capacity
Down - 108-132 seconds.
Standard - 230 kg (500 lb.).
Extend-A-Reach
Boom Elevation
Up - 15-25 seconds.
Main boom - -14° to +75°.
Down - 15-25 seconds.
Extend-A-Reach - +15° to -80°.
Machine Weight
Swing Speed 360°
143-243 seconds.
Approximately 19,958 kg (44,000 lb.).
Maximum Tire Load
11,834 kg (26,090 lb.) @ 10 bar (149 psi).
Platform Rotation
Left - 20-30 seconds.
Right - 20-30 seconds.
Machine Height (Stowed)
3.1 m (10 ft. 3-27/32 in.).
Ground to 120’
257-330 seconds.
Machine Length (Stowed)
Boom erected for use - 15.9 m (52 ft. 4 in.).
From 120’ to Ground
Boom stowed for shipping - 10.9 m (35 ft. 10-5/8 in.).
248 to 307 seconds.
Machine Width
Ground to 120’ to Ground
2.6 m (8 ft. 6 in.) w/axles retracted.
505 to 637 seconds.
3.3 m (10 ft. 10 in.) w/ axles extended.
Wheelbase
3.5 m (11 ft. 4-1/2 in.).
1-2
– JLG Lift –
3120819
SECTION 1 - SPECIFICATIONS
1.5
FUNCTION SPEEDS (MACHINES BUILT
AFTER S/N 38697)
1.6
TORQUE REQUIREMENTS
Table 1-1. Torque Requirements
Telescope
Description
Extend - 80-100 seconds.
Retract - 85-100 seconds.
Torque Value
(Dry)
Interval Hours
Bearing To Chassis
298 NM
(220 FT LB)
200/500*
Bearing To Turntable
298 NM
(220 FT LB)
200/500*
Wheel Lugs
407 NM
(300 FT LB)
50
Drive Torque Hub to
Spindle
353 NM
(260 FT LB )
500
Boom Chains
80 NM
(59 FT LB)
200
Swing Motor to Swing
Brake
102 NM
(75 FT LB)
500
Swing Brake to
Torque Hub
149 NM
(110 FT LB )
500
Ground to 120’
Torque Hub to Mounting Plate
353 NM
(260 FT LB )
500
165 to 200 seconds.
Frame Valve Bolts
9 NM
(80 IN LB)
See Note
Below**
Lift
Up - 85-100 seconds.
Down - 75-100 seconds.
Extend-A-Reach
Up - 15-25 seconds.
Down - 15-25 seconds.
Swing Speed 360°
143-243 seconds.
Platform Rotation
Left - 7-20 seconds.
Right - 7-20 seconds.
From 120’ to Ground
150 to 200 Seconds
Ground to 120’ to Ground
315 to 400 Seconds
* Retorque swing bearing bolts after first 200 hours of operation and every 500 hours thereafter.
**Re-torque frame valve bolts after checking or adjusting
steer pressure.
NOTE: See Section 2 for tightening sequence of turntable
bearing bolts.
NOTE: When maintenance becomes necessary or a fastener has loosened, refer to the Torque Chart Figure
1-1 to determine proper torque value.
3120819
– JLG Lift –
1-3
Figure 1-1. Torque Chart
SECTION 1 - SPECIFICATIONS
1-4
– JLG Lift –
3120819
SECTION 1 - SPECIFICATIONS
1.7
Hydraulic Oil
LUBRICATION
Table 1-4. Hydraulic Oil
Engine (Crankcase) Oil
NOTE: Crankcase oil must be a high quality detergent type
meeting one of the following API service classifications: CC/SE, CC/SF, CD/SE, CD/SF, CE/SF or CE/
SG.l
HYDRAULIC SYSTEM OPERATING
TEMPERATURE RANGE
SAE VISCOSITY
GRADE
-18° C to -5° C (0° F to +23° F)
10W
-18° C to +99° C (0° F to +210° F)
10W-20, 10W30
+10° C to +99° C (+50° F to +210° F)
20W-20
Table 1-2. Single Viscosity Oil
When Outside Temperature is
Consistently
Use SAE Viscosity
Number
-29° C to -4° C (-20° F to +25° F)
*10W
-10° C to +10° C (+15° F to +50° F)
20W-20
+4° C to +30° C (+40° F to ++85° F)
30
Above +24° C (Above +75° F )
40
NOTE: When temperatures remain consistently below -7
degrees C. (20 degrees F.), JLG Industries recommends the use of Mobil DTE11.
Table 1-3. Multi Viscosity Oil
When Outside Temperature is
Consistently
NOTE: Aside from JLG recommendations, it is not advisable
to mix oils of different brands or types, as they may
not contain the same required additives or be of
comparable viscosities. If use of hydraulic oil other
than Mobilfluid 424 is desired, contact JLG Industries for proper recommendations.
Use SAE
Viscosity
Number
-40° C to +24° C (-40° F to +75° F)
*5W-20
(synthetic)
-21° C to +21° C (-5° F to +70° F)
10W-30
-21° C to +30° C (-5° F to +85° F)
10W-40
-10° C to +24° C (+15° F to +75° F)
15W-30
-10° C and above (Above +15° F)
15W-40
* This viscosity can be used at colder temperatures only
with engine oil preheating.
3120819
NOTE: Hydraulic oils must have anti-wear qualities at least
to API Service Classification GL-3, and sufficient
chemical stability for mobile hydraulic system service. JLG Industries recommends Mobilfluid 424
hydraulic oil, which has an SAE viscosity index of
152 or Kendall Hyken 052 hydraulic oil, which has an
SAE viscosity of 10W-20 and viscosity index of 152.
Some machines may be specially equipped with Mobil
EAL224H biodegradable and non-toxic hydraulic oil. This
oil is vegetable oil based and possesses the same antiwear and rust protection characteristics as mineral oils,
but will not adversely affect ground water or the environment when spilled or leaked in small amounts. Mobil
EAL224H has a viscosity of 34 cST at 40° C and a viscosity
index of 213. The operating range of this oil is -18° C to
+83° C.
– JLG Lift –
1-5
SECTION 1 - SPECIFICATIONS
IT IS RECOMMENDED THAT MOBIL EAL224H HYDRAULIC OIL BE
STORED ABOVE FREEZING (0 C) AS THE OIL MAY APPEAR
CLOUDY AFTER EXPOSURE TO LOW TEMPERATURES FOR
EXTENDED PERIODS OF TIME. THE CLOUDINESS WILL DISAPPEAR
WHEN THE OIL IS WARMED TO AT LEAST 10 C AND AGITATED. DO
NOT ATTEMPT TO "THIN" THE OIL WITH NO.2 DIESEL FUEL. FOR
BEST RESULTS, STORE THE OIL ABOVE FREEZING.
NOTE: Accidentally mixing Mobil EAL224H hydraulic oil with
other mineral oils will cause no loss of performance
characteristics. However, biodegradability may be
reduced and toxicity may be increased, depending
on the oil and level of contamination.
Lubrication Specifications
Table 1-5. Lubrication Specifications
KEY
SPECIFICATIONS
MPG
Multipurpose Grease having a minimum dripping
point of 350° F. Excellent water resistance and
adhesive qualities, and being of extreme pressure type. (Timken OK 40 pounds minimum.)
EPGL
Extreme Pressure Gear Lube (oil) meeting API
service classification GL-5 or MIL-Spec MIL-L2105.
HO
Hydraulic Oil. API service classification GL-3, e.g.
Kendall Hyken 052 or Mobilfluid 424.
EO
Engine (crankcase) Oil. Gas - API SG/SH class,
MIL-L-2104. Diesel - API CC/CD/CE class, MIL-L2104B/MIL-L-2104C.
NOTE: Refer to Figure 1-2 for specific lubrication procedures.
1-6
– JLG Lift –
3120819
Figure 1-2. Lubrication Diagram
SECTION 1 - SPECIFICATIONS
3120819
– JLG Lift –
1-7
SECTION 1 - SPECIFICATIONS
Table 1-6. Lubrication Chart
Index
No.
Number/Type
Lube Points
Component
Lube &
Method
Interval
Hours
Comments
Check Every 150 Hours/Change Every
1200 Hours
1
Wheel Drive Hubs
Fill/Drain Plugs
EPGL (SAE 90)
150/
1200
2
Steer Cylinders - Rod End
2 Grease Fitting
MPG - Pressure Gun
150
3
Steer Cylinders - Barrel End
2 Grease Fittings
MPG - Pressure Gun
150
4
King Pins
4 Grease Fittings
MPG - Pressure Gun
150
5
Tie Rods
4 Grease Fitting
MPG - Pressure Gun
150
6
Rotary Platform Stand
Rotary Worm Gear
2 Grease Fittings
N/A
MPG - Pressure Gun
MPG - Brush
150
150
7
Platform Level cylinder
3 Grease Fittings
MPG - Pressure Gun
150
8
Platform Pivot Pin
1 Grease Fitting
MPG - Pressure Gun
150
9
Link Level Pin
2 Grease Fittings
MPG - Pressure Gun
150
10
E-A-R Pivot Pin
1 Grease Fitting
MPG - Pressure Gun
150
11
E-A-R Lift Cylinder - Rod End
1 Grease Fitting
MPG - Pressure Gun
150
12
E-A-R Lift Cylinder - Barrel End
1 Grease Fitting
MPG - Pressure Gun
150
13
Sheave Pin - Fly Extend
1 Grease Fitting
MPG - Pressure Gun
150
14
Sheave Pin - Upper Aux.
1 Grease Fitting
MPG - Pressure Gun
150
15
Tele Cyl. Sheave Pin
1 Grease Fitting
MPG - Pressure Gun
150
Extend boom until grease fitting is accessible thru hole in fly sec.
16
Boom Chains
N/A
Chain Lube/Hot Oil
Dip
1200
Extend and Retract Chains
17
Sheave Pin - Fly Retract
2 Grease Fittings
MPG - Pressure Gun
150
Extend boom until fitting is accessible
thru hole in fly
18
Sheave Pin - Outer-Mid Retract
2 Grease Fittings
MPG - Pressure Gun
150
Extend boom until fitting is accessible
thru hole in fly
19
Lift Cylinder - Barrel End
1 Grease Fitting
MPG - Pressure Gun
150
Remote Access
20
Master Cylinder - Barrel End
1 Grease Fitting
MPG - Pressure Gun
150
Remote Access
21
Swing Bearing
1 Grease Fitting
MPG - Pressure Gun
150
Remote Access. Lube, rotate 180 , lube
again.
22
Swing Bearing Gear
N/A
MPG - Brush
150
23
Master Cylinder - Rod End
1 Grease Fitting
MPG - Pressure Gun
150
24
Boom Pivot Bearings
2 Grease Fittings
MPG - Pressure Gun
150
25
Lift Cylinder - Rod End
1 Grease Fitting
MPG - Pressure Gun
150
1-8
– JLG Lift –
Remove Cover to Grease
3120819
SECTION 1 - SPECIFICATIONS
Table 1-6. Lubrication Chart
Index
No.
Number/Type
Lube Points
Component
Lube &
Method
Interval
Hours
150
Comments
26
Load Moment Pivot Pins
1 Grease Fitting
MPG - Pressure Gun
27
Hydraulic Filter - Function
Pump
N/A
N/A
50/300
Replace after first 50 hrs. of operation,
then every 300 hrs. thereafter
28
Hydraulic Filter - Drive Pump
N/A
N/A
50/300
Replace after first 50 hrs. of operation,
then every 300 hrs. thereafter
29
Hydraulic Fluid
Fill Cap
HO
10/1200
Check oil daily/Change oil every 1200
hrs
30
Engine Crankcase
Fill Cap/Drain Plug
EO - SAE30
10/300
Check oil daily/Change oil every 300 hrs.
31
Engine Oil Filter
N/A
Replaceable Cartridge
300
32
Platform Door Hinges
2 Grease Fittings
MPG - Pressure Gun
150
33
Access Door Hinges
N/A
SAE10 - Oil Can
150
As Needed
34
Access Door Latches
N/A
SAE10 - Oil Can
150
As Needed
35
Axle Beams
N/A
MPG - Brush
600
As Needed
Key to Lubricants:
MPG - Multipurpose Grease
EPGL - Extreme Pressure Gear Lubricant
HO - Hydraulic Fluid
EO - Engine Oil
3120819
– JLG Lift –
Position boom over side for access
under turntable
1-9
SECTION 1 - SPECIFICATIONS
1.8
Frame Mounted Control Valve
PRESSURE SETTINGS - PSI (BAR)
Front Steer Relief - 2000 (138)
NOTE: All pressures are given in pounds per square inch
(psi), with the metric equivalent, bar, given in parentheses.
Rear Steer Relief - 2000 (138)
Front Axle Extend Relief - 2000 (138)
Main Control Valve
Front Axle Retract Relief - 2200 (152)
Main Relief - 3450 (238)
Rear Axle Extend Relief - 2000 (138)
Lift Down Relief - 1200 (83)
Rear Axle Retract Relief - 2200 (152)
Swing Relief - 1200 (83)
Level Up Relief - 2500 (172)
Level Down Relief - 2000 (138)
Rotate Relief - 2500 (172)
Extend-A-Reach Up Relief - 3000 (207)
Extend-A-Reach Down Relief - 1400 (97)
Sequence (Load Sense) - 160 (11)*
* Sequence pressure is pre-set and not normally
adjusted.
1-10
– JLG Lift –
3120819
SECTION 1 - SPECIFICATIONS
Figure 1-3. Serial Number Locations
1.9
SERIAL NUMBER LOCATIONS
1.10 MAJOR COMPONENT WEIGHTS
For machine identification, a serial number plate is affixed
to the machine. The plate is located on the left side of the
frame, between the bearing area and the left rear wheel. If
the serial number plate is damaged or missing, the
machine serial number is stamped on the left side of the
frame, at the center top, below the turntable bearing; the
serial number is also stamped on the left side of the turntable, at center, along the left turntable upright close to the
bearing area. In addition, the last five digits of the serial
number are stamped on the top left of the fly end of each
boom section.
Table 1-7. Major Component Weights
COMPONENT
Platform - 36 x 72 in. (0.9 x
1.8 m) w/Control Box Support and Rotator.
243(110)
Boom (Less Extend-AReach Jib and Platform)
9,502 (4310)
Jib, Extend-A-Reach and
Pivot Attach
789(358)
Turntable Complete (Less
Counterweight)
9,101 (4,128)
Counterweight
9,050 (4,105)
Lift Cylinder
Level Cylinder
Frame Complete (Includes
Tires and Wheels)
3120819
LB (KG)
809 (367)
60 (27)
14,400 (6,532)
Wheel and Tire Assembly
(Each)
933 (423)
Complete Machine - 4WD
44,004 (19,960)
– JLG Lift –
1-11
SECTION 1 - SPECIFICATIONS
1.11 BOOM TAPE
1.13 CRITICAL STABILITY WEIGHTS
Standard Boom
Table 1-9. Critical Stability Weights
Red Tape - 56-1/2 in. (143.5 cm).
COMPONENT
White Tape - 91-5/8 in. (232.7 cm)
Counterweight
w/Boom Wipers
Red Tape - 54-1/2 in. (138.4 cm).
WEIGHT
9, 050 lb. (4,105 kg)
Foam-Filled Tires (each)
932 lb. (423 kg)
Deutz Engine
837 lb. (380 kg)
Platform
243 lb. (110 kg)
White Tape - 89-5/8 in. (227.6 cm).
1.12 CYLINDER SPECIFICATIONS
NOTE: All dimensions are given in inches (in.), with the metric equivalent, centimeters (cm), given in parentheses.
Table 1-8. Cylinder Specifications
BORE
STROKE
ROD
DIA.
9.0
(22.9)
48.5
(123.2)
4.0
(10.2)
Master Cylinder
2.5
(6.4)
15.1
(38.4)
1.3
(3.2)
Slave Cylinder
3.5
(8.9)
7.3
(18.5)
1.8
(4.4)
Extend-A-Reach
Cyl.
3.5
(8.9)
18.3
(46.5)
2.5
(6.4)
Telescope Cylinder
5.0
(12.7)
266.0
(675.6)
3.5
(8.9)
Frame Jack Cyl. (2)
5.0
(12.7)
17.6
(44.8)
3.0
(7.6)
Axle Extend Cyl. (2)
3.0
(7.6)
29.0
(73.7)
2.0
(5.1)
Steer Cylinder (2)
3.0
(7.6)
9.8
(24.9)
1.5
(3.8)
DESCRIPTION
Lift Cylinder
1-12
DO NOT REPLACE ITEMS CRITICAL TO STABILITY, SUCH AS THE
COUNTERWEIGHT OR FOAM-FILLED TIRES, WITH ITEMS OF DIFFERENT WEIGHT OR SPECIFICATION. DO NOT MODIFY UNIT IN
ANY WAY TO AFFECT STABILITY.
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
SECTION 2. PROCEDURES
2.1
2. At any time when air, fuel, or oil lines are disconnected, clear adjacent areas as well as the openings
and fittings themselves. As soon as a line or component is disconnected, cap or cover all openings to
prevent entry of foreign matter.
GENERAL
This section provides information necessary to perform
maintenance on the aerial platform. Descriptions, techniques and specific procedures are designed to provide
the safest and most efficient maintenance for use by personnel responsible for ensuring the correct installation
and operation of machine components and systems.
WHEN AN ABNORMAL CONDITION IS NOTED AND PROCEDURES
CONTAINED HEREIN DO NOT SPECIFICALLY RELATE TO THE
NOTED IRREGULARITY, WORK SHOULD BE STOPPED AND
TECHNICALLY QUALIFIED GUIDANCE OBTAINED BEFORE WORK
IS RESUMED.
3. Clean and inspect all parts during servicing or maintenance, and assure that all passages and openings
are unobstructed. Cover all parts to keep them
clean. Be sure all parts are clean before they are
installed. New parts should remain in their containers until they are ready to be used.
Components Removal and Installation
1. Use adjustable lifting devices, whenever possible, if
mechanical assistance is required. All slings (chains,
cables, etc.) should be parallel to each other and as
near perpendicular as possible to top of part being
lifted.
The maintenance procedures included consist of servicing and component removal and installation, disassembly
and assembly, inspection, lubrication and cleaning. Information on any special tools or test equipment is also provided where applicable.
2.2
2. Should it be necessary to remove a component on
an angle, keep in mind that the capacity of an eyebolt or similar bracket lessens, as the angle between
the supporting structure and the component
becomes less than 90 degrees.
SERVICING AND MAINTENANCE
GUIDELINES
3. If a part resists removal, check to see whether all
nuts, bolts, cables, brackets, wiring, etc., have been
removed and that no adjacent parts are interfering.
General
The following information is provided to assist you in the
use and application of servicing and maintenance procedures contained in this chapter.
Safety and Workmanship
Your safety, and that of others, is the first consideration
when engaging in the maintenance of equipment. Always
be conscious of weight. Never attempt to move heavy
parts without the aid of a mechanical device. Do not allow
heavy objects to rest in an unstable position. When raising
a portion of the equipment, ensure that adequate support
is provided.
Cleanliness
Component Disassembly and Reassembly
When disassembling or reassembling a component, complete the procedural steps in sequence. Do not partially
disassemble or assemble one part, then start on another.
Always recheck your work to assure that nothing has been
overlooked. Do not make any adjustments, other than
those recommended, without obtaining proper approval.
Pressure-Fit Parts
When assembling pressure-fit parts, use an “anti-seize” or
molybdenum disulfide base compound to lubricate the
mating surface.
Bearings
1. The most important single item in preserving the
long service life of a machine is to keep dirt and foreign materials out of the vital components. Precautions have been taken to safeguard against this.
Shields, covers, seals, and filters are provided to
keep air, fuel, and oil supplies clean; however, these
items must be maintained on a scheduled basis in
order to function properly.
3120819
– JLG Lift –
1. When a bearing is removed, cover it to keep out dirt
and abrasives. Clean bearings in nonflammable
cleaning solvent and allow to drip dry. Compressed
air can be used but do not spin the bearing.
2. Discard bearings if the races and balls (or rollers)
are pitted, scored, or burned.
2-1
SECTION 2 - PROCEDURES
3. If bearing is found to be serviceable, apply a light
coat of oil and wrap it in clean (waxed) paper. Do not
unwrap reusable or new bearings until they are
ready to install.
4. Lubricate new or used serviceable bearings before
installation. When pressing a bearing into a retainer
or bore, apply pressure to the outer race. If the bearing is to be installed on a shaft, apply pressure to the
inner race.
Gaskets
Check that holes in gaskets align with openings in the
mating parts. If it becomes necessary to hand-fabricate a
gasket, use gasket material or stock of equivalent material
and thickness. Be sure to cut holes in the right location, as
blank gaskets can cause serious system damage.
Lubrication
Service applicable components with the amount, type,
and grade of lubricant recommended in this manual, at
the specified intervals. When recommended lubricants are
not available, consult your local supplier for an equivalent
that meets or exceeds the specifications listed.
Battery
Clean battery, using a non-metallic brush and a solution of
baking soda and water. Rinse with clean water. After
cleaning, thoroughly dry battery and coat terminals with
an anti-corrosion compound.
Lubrication and Servicing
Components and assemblies requiring lubrication and
servicing are shown in Figure 1-2.
Bolt Usage and Torque Application
1. Use bolts of proper length. A bolt which is too long
will bottom before the head is tight against its related
part. If a bolt is too short, there will not be enough
thread area to engage and hold the part properly.
When replacing bolts, use only those having the
same specifications of the original, or one which is
equivalent.
2.3
LUBRICATION INFORMATION
Hydraulic System
1. The primary enemy of a hydraulic system is contamination. Contaminants enter the system by various
means, e.g., using inadequate hydraulic oil, allowing
moisture, grease, filings, sealing components, sand,
etc., to enter when performing maintenance, or by
permitting the pump to cavitate due to insufficient
system warm-up or leaks in the pump supply (suction) lines.
2. Unless specific torque requirements are given within
the text, standard torque values should be used on
heat-treated bolts, studs, and steel nuts, in accordance with recommended shop practices. (See Figure 1-1.)
2. The design and manufacturing tolerances of the
component working parts are very close, therefore,
even the smallest amount of dirt or foreign matter
entering a system can cause wear or damage to the
components and generally results in faulty operation. Every precaution must be taken to keep
hydraulic oil clean, including reserve oil in storage.
Hydraulic system filters should be checked,
cleaned, and/or replaced as necessary, at the specified intervals required in Figure 1-2. Always examine
filters for evidence of metal particles.
Hydraulic Lines and Electrical Wiring
Clearly mark or tag hydraulic lines and electrical wiring, as
well as their receptacles, when disconnecting or removing
them from the unit. This will assure that they are correctly
reinstalled.
Hydraulic System
1. Keep the system clean. If evidence of metal or rubber particles are found in the hydraulic system, drain
and flush the entire system.
3. Cloudy oils indicate a high moisture content which
permits organic growth, resulting in oxidation or corrosion. If this condition occurs, the system must be
drained, flushed, and refilled with clean oil.
2. Disassemble and reassemble parts on clean work
surface. Clean all metal parts with non-flammable
cleaning solvent. Lubricate components, as
required, to aid assembly.
4. It is not advisable to mix oils of different brands or
types, as they may not contain the same required
additives or be of comparable viscosities. Good
grade mineral oils, with viscosities suited to the
ambient temperatures in which the machine is operating, are recommended for use.
NOTE: Metal particles may appear in the oil or filters of new
machines due to the wear-in of meshing components.
2-2
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Hydraulic Oil
Lubrication Specifications
1. Refer to Table 1-1 for recommendations for viscosity
ranges.
2. JLG recommends Kendall Hyken 052 hydraulic oil,
which has an SAE viscosity of 10W-20 and a viscosity index of 152 or Mobilfluid 424 hydraulic oil, which
has an SAE viscosity of 10W-30 and a viscosity
index of 152. Kendall Hyken 052 and Mobilfluid 424
are fully compatible, and can be mixed as necessary.
NOTE: Start-up of hydraulic system with oil temperatures
below -26 degrees C (-15 degrees F). is not recommended. If it is necessary to start the system in a
sub-zero environment, it will be necessary to heat
the oil with a low density, 100VAC heater to a minimum temperature of -26 degrees C (-15 degrees F).
3. The only exception to the above is to drain and fill
the system with Mobil DTE 11 oil or its equivalent.
This will allow start up at temperatures down to -29
degrees C (-20 degrees F). However, use of this oil
will give poor performance at temperatures above
49 degrees C (120 degrees F). Systems using DTE
11 oil should not be operated at temperatures above
94 degrees C (200 degrees F) under any condition.
Changing Hydraulic Oil
1. Use of any of the recommended crankcase or
hydraulic oils eliminates the need for changing the
oil on a regular basis. However, filter elements must
be changed after the first 40 hours of operation and
every 250 hours thereafter. If it is necessary to
change the oil, use only those oils meeting or
exceeding the specifications appearing in this manual. If unable to obtain the same type of oil supplied
with the machine, consult local supplier for assistance in selecting the proper equivalent. Avoid mixing petroleum and synthetic base oils. JLG
Industries recommends changing the hydraulic oil
annually.
2. Use every precaution to keep the hydraulic oil clean.
If the oil must be poured from the original container
into another, be sure to clean all possible contaminants from the service container. Always clean the
mesh element of the filter and replace the cartridge
any time the system oil is changed.
3. While the unit is shut down, a good preventive maintenance measure is to make a thorough inspection
of all hydraulic components, lines, fittings, etc., as
well as a functional check of each system, before
placing the machine back in service.
3120819
Specified lubricants, as recommended by the component
manufacturers, are always the best choice, however,
multi-purpose greases usually have the qualities which
meet a variety of single purpose grease requirements.
Should any question arise regarding the use of greases in
maintenance stock, consult your local supplier for evaluation. Refer to Table 1-2 for an explanation of the lubricant
key designations appearing in the Lubrication Chart.
2.4
CYLINDERS - THEORY OF OPERATION
Cylinders are of the double acting type. Systems incorporating double acting cylinders are as follows: Lift, Telescope, Steer, Master Level, Slave Level, Frame Lift, Axle
Extend and Extend-A-Reach. A double acting cylinder is
one that requires oil flow to operate the cylinder rod in
both directions. Directing oil (by actuating the corresponding control valve to the piston side of the cylinder)
forces the piston to travel toward the rod end of the barrel,
extending the cylinder rod (piston attached to rod). When
the oil flow is stopped, movement of the rod will stop. By
directing oil to the rod side of the cylinder, the piston will
be forced in the opposite direction and the cylinder rod
will retract.
Holding valves are used in the Lift, Platform Level, Telescope, and Extend-A-Reach circuits to prevent retraction
of the cylinder rod should a hydraulic line rupture or a leak
develop between the cylinder and its related control valve.
2.5
VALVES - THEORY OF OPERATION
Solenoid Control Valves (Bang-Bang)
Control valves used are four-way three-position solenoid
valves of the sliding spool design. When a circuit is activated and the control valve solenoid energizes, the spool
is shifted and the corresponding work port opens to permit oil flow to the component in the selected circuit, with
the opposite work port opening to reservoir. Once the circuit is deactivated (control returned to neutral), the valve
spool returns to neutral (center) and oil flow is then
directed through the valve body and returns to reservoir. A
typical control valve consists of the valve body, sliding
spool, and two solenoid assemblies. The spool is
machine fitted in the bore of the valve body. Lands on the
spool divide the bore into various chambers, which, when
the spool is shifted, align with corresponding ports in the
valve body open to common flow. At the same time other
ports would be blocked to flow. The spool is springloaded to center position, therefore when the control is
released, the spool automatically returns to neutral, prohibiting any flow through the circuit.
– JLG Lift –
2-3
SECTION 2 - PROCEDURES
Manual Hydraulic Control Valves
2.6
The manual hydraulic control valves consist of four-way,
multi-position valve sections, each section incorporating a
sliding spool, spring-loaded to neutral or off. Each spool is
attached to a control lever which provides for proportional
control of the selected system function. This proportional
control enables metering of oil flow in accordance with
spool position, affording variable and smooth speed control capability. Spool movement causes work ports within
the valve to align in a predetermined way, permitting flow
to the selected function, with the opposing work ports
positioned to allow return flow to the hydraulic reservoir.
Adjusting Procedures
ENSURE MACHINE IS ON A FIRM AND LEVEL SURFACE.
1. Position boom fully retracted at +5 degrees horizontal, no load in platform.
2. Torque outer mid section extend chain adjuster to 80
Nm (59 ft. lb.).
Relief Valves
Main relief valves are installed at various points with the
hydraulic system to protect associated systems and components against excessive pressure. Excessive pressure
can be developed when a cylinder reaches its limit of
travel and the flow of pressurized fluid continues from the
system control. The relief valve provides an alternate path
for the continuing flow from the pump, thus preventing
rupture of the cylinder, hydraulic line or fitting. Complete
failure of the system pump is also avoided by relieving circuit pressure. The relief valve is installed in the circuit
between the pump outlet (pressure line) and the cylinder
of the circuit, generally as an integral part of the system
valve bank. Relief pressures are set slightly higher than
the load requirement, with the valve diverting excess
pump delivery back to the reservoir when operating pressure of the component is reached.
BOOM CHAINS
3. Torque outer mid section retract chain adjuster to 80
Nm (59 ft. lb.).
4. Torque fly section extend chain adjuster to 80 Nm
(59 ft. lb.).
5. Torque fly section retract chain adjuster to 80 Nm
(59 ft. lb.).
6. Cycle boom (extend at least 2 meters (6 feet), then
retract fully).
7. Recheck outer mid section extend chain.
8. Recheck outer mid section retract chain.
9. Recheck fly section extend chain.
10. Recheck fly section retract chain.
11. Repeat steps (2) thru (10) if necessary.
Crossover Relief Valves
12. Check for proper operation of boom.
Crossover relief valves are used in circuits where the actuator requires an operating pressure lower than that supplied to the system. When the circuit is activated and the
required pressure at the actuator is developed, the crossover relief diverts excess pump flow to the reservoir. Individual, integral reliefs are provided for each side of the
circuit.
JLG Industries, Inc. requires a complete boom disassembly, per the instructions outlined in paragraph 2-11, Boom
Maintenance, every two years. All boom chains and
related components (i.e., sheaves, pins, sprockets, wear
pads, etc.) must also be inspected and replaced, as necessary, during this disassembly.
2-4
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Figure 2-1. Boom Chain Adjustments
3120819
– JLG Lift –
2-5
SECTION 2 - PROCEDURES
Figure 2-2. Typical Boom Assembly
An immediate disassembly of the boom assembly and
inspection of the boom chains and related components is
required if any of the following conditions occur:
Inspection Procedure
1. After machine is exposed to hostile environments or
conditions (i.e., extreme cold, dust, sand, blasting
grit, salt, chemicals, etc.) which could adversely
affect boom operation.
BOOM CHAINS TO BE INSPECTED AT TIME OF NEXT BOOM
OVERHAUL AND WHEN DEEMED NECESSARY BY MACHINE
OWNER, BUT NOT TO EXCEED 2 YEARS OF MACHINE OPERATION.
2. Erratic boom operation or unusual noise exists.
Refer to troubleshooting tables in Section 3.
1. Inspect boom chains for the following conditions:
3. Chain adjustment is required more often than specified in this Section or links need to be removed
(chain shortened) to make adjustment.
4. Machine is idle for an extended period (6 months or
longer).
5. Boom is overloaded or has sustained a shock load.
FAILURE TO DISASSEMBLE THE BOOM ASSEMBLY AND PROPERLY INSPECT AND/OR REPLACE THE BOOM CHAINS AND
RELATED COMPONENTS (I.E., SHEAVES, PINS, SPROCKETS,
WEAR PADS, ETC.) COULD RESULT IN THE DAMAGE AND/OR
BREAKAGE OF THE BOOM CHAINS AND/OR RELATED COMPONENTS. DAMAGE AND/OR BREAKAGE OF THESE ITEMS COULD
RESULT IN UNCONTROLLED EXTENSION OR RETRACTION OF
THE BOOM ASSEMBLY AND COULD CAUSE SERIOUS INJURY OR
DEATH TO PERSONNEL OPERATING THE JLG BOOM LIFT.
2-6
– JLG Lift –
a. Wear: Always inspect that segment of chain that
operates over a sheave. As the chain flexes over
the extend/retract sheaves, joints and plate
edges very gradually wear. Chain “stretch” can
be measured using a manufacturers wear scale
or steel tape. When chains have elongated 3%
they must be removed and replaced. Refer to
Table 2-1 for proper chain specifications and
allowable stretch tolerances. Peening and wear
of chain plate edges are caused by sliding over
a chain worn contact face of a sheave, or unusually heavy loads. All of the above require
replacement of the chain and correction of the
cause. Chain side wear, noticeable when pin
heads and outside plates show a definite wear
pattern, is caused by misalignment of the
sheave/chain anchors and must be corrected
promptly. Do not repair chains; if a section of
chain is damaged, replace the entire chain set.
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SECTION 2 - PROCEDURES
b. Lubrication: One of the most important but often
overlooked factors is adequate lubrication. In
addition to reducing internal friction, maintaining
a film of oil on all chain surfaces will inhibit rusting and corrosion. This is important as corrosion
of highly stressed, hardened steel chain components can cause a major reduction in the load
capacity of leaf chain and result in link plate
cracking.
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:
NOTE: The need for lubrication can be determined by the
presence of rust on the exposed portions of chain.
Oil rusty chains, and replace chains with bent or
peened chain components. Keep chains lubricated.
c. Rust and Corrosion: Rust and corrosion will
cause a major reduction in the load carrying
capacity of the chain, because these are primary
reasons for side plate cracking. The initial lubrication at the factory is applied in a hot dip tank
to assure full penetration into the joint. Do not
steam clean or degrease this lubricant of
chains. At time of chain installation, factory lube
must be supplemented by a maintenance program to provide a film of oil on the chains at all
times. A grade of SAE 30 or 40 weight, nondetergent motor oil should be used as a supplemental lubricant and a film of this oil should be
constantly maintained on the surfaces and internal joints. If chains are corroded, they must be
inspected, especially the outside plates, for
cracks in-line with the pins. If cracks are found,
replace the chain; if no cracks are discovered,
lubricate the chains by dipping in heated oil, and
reinstall on the machine. Keep chains lubricated.
1. Bent pins or plates.
2. Rusty joints.
3. Peened plate edges.
TIGHT JOINTS
f. Protruding or Turned Pins: Chains operating
with inadequate lube generate tremendous friction between the pin and plates (pin and bushing on roller chain). In extreme cases, this
frictional torque can actually turn the pins in the
outside press-fit plates. Inspect for turned pins,
which can be easily spotted as the “V” flats on
the pin heads are no longer in line. Replace all
chains showing evidence of turned or protruding
pins. Keep chains lubricated.
ABNORMAL PROTRUSION OR
TURNED PINS
d. Fatigue Cracks: Fatigue is a phenomenon that
affects most metals, and is the most common
cause of chain plate failures. Fatigue cracks are
found through the link holes, perpendicular (90
degrees) from the pin in-line position. Inspect
chains carefully after long time use and heavy
loading for this type of crack. If any cracks are
discovered, replace all chains, as seemingly
sound plates are on the verge of cracking.
Fatigue and ultimate strength failures on JLG
Lifts are incurred as a result of severe abuse as
design specs are well within the rated lifting
capacity of these chains..
g. Stress Corrosion Cracking: The outside link
plates, which are heavily press-fitted to the pins,
are particularly susceptible to stress corrosion
cracking. Like fatigue cracks, these initiate at the
point of highest stress (aperture) but tend to
extend in an arc-like path, often parallel to the
rolling grain of the material.
e. Tight Joints: All joints in the roller chain should
flex freely. On roller chain, tight joints are usually
caused by rust/corrosion, or the inside plates
“walking” off the bushing. Limber up rusty/corroded chains (after inspecting carefully) with a
heavy application of oil (preferably a hot oil dip).
Tap inside “walking” plates inward; if “walking”
Also, more than one crack can often appear on a
link plate. In addition to rusting, this condition
can be caused by exposure to an acidic or caustic medium or atmosphere. Stress corrosion is
an environmentally assisted failure. Two conditions must be present - corrosive agent and
static strees. In the chain, static stress is present
at the aperture due to the press fit pin. No cycle
motion is required and the plates can crack during idle periods. The reactions of many chemical
agents (such as battery acid fumes) with hard-
3120819
– JLG Lift –
2-7
SECTION 2 - PROCEDURES
ened metals liberate hydrogen which attacks
and weakens the metal grain structure.
ARC-LIKE CRACKED PLATES
(STRESS CORROSION)
2.8
NOTE: It is recommended that the machine be shut down in
the test mode for at least one hour prior to beginning
the drift test. This will allow the oil temperature in the
cylinder to stabilize with the ambient temperature.
Thermal expansion or retraction of the hydraulic oil
can greatly affect cylinder movement.
h. Chain Anchors and Sheaves: An inspection of
the chain must include a close examination of
chain anchors and sheaves. Check chain
anchors for wear breakage and misalignment.
Anchors with worn or broken fingers should be
replaced. They should also be adjusted to eliminate twisting the chain for an even load distribution.
Sheaves should be inspected for worn flanges,
which would indicate misalignment, and wear on
the outside diameter of the sheave. A worn
sheave can mean several problems, as follows:
1. Chains too tight.
2. Sheave bearings/pin bad.
3. Bent/misaligned chains.
Telescope Cylinder
NOTE: Switches referenced in this procedure are located on
the Ground Control Panel.
1. Activate hydraulic system, properly set extendable
axles and position boom in stowed position; adhere
to all safety precautions.
BEFORE RAISING AND EXTENDING BOOM, ENSURE THAT
AREAS ABOVE AND BELOW BOOM AND PLATFORM AND AHEAD
OF PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PERSONNEL.
2. Position LIFT control switch to UP and hold until
boom reaches horizontal.
Table 2-1. Chain Stretch Tolerance
3. Position TELESCOPE control switch to OUT and
hold until boom extends approximately 1.2 meter (4
feet); measure from end of base section to end of
mid section.
ALLOWABLE
STRETCH 14 IN.
SPAN
CHAIN SIZE
PIN TO PIN
MEASUREMENT
0.50 in. (1.27 cm)
pitch
36 cm (14 in.) or
28 pitches
1.07 cm (0.42 in.)
1.00 in. (2.54 cm)
pitch
36 cm (14 in.) or
14 pitches
1.07 cm (0.42 in.)
1.75 in. (4.45 cm)
pitch
36 cm (14 in.) or 8
pitches
1.07 cm (0.42 in.)
2.00 in. (5.08 cm)
pitch
36 cm (14 in.) or 7
pitches
1.07 cm (0.42 in.)
2.7
DRIFT TEST
4. Position LIFT control switch to UP and hold until
boom reaches maximum elevation. Shut down
engine.
5. Tag and carefully disconnect the hydraulic lines to
the telescope cylinder at control valve.
6. Observe oil flow from cylinder lines. Oil leaking from
extend port hose indicates a leaking counterbalance
valve. Oil leaking from retract port hose indicates
leakage by cylinder piston.
7. Leave boom elevated in test position for approximately one hour.
WEAR PADS
Shim up wear pads to within 1.6 mm (1/16 in.) tolerance
between wear pad and adjacent surface.
Replace wear pads when worn within 3.2 mm (1/8 in.) of
threaded insert.
BEFORE LOWERING BOOM, ENSURE THAT AREAS BELOW
BOOM AND PLATFORM ARE CLEAR OF ALL PERSONNEL AND
OBSTRUCTIONS.
8. Position LIFT control switch to DOWN and hold until
boom reaches horizontal; check boom length
against measurement. If boom has retracted more
than 2.5 cm (1 inch) and oil is leaking around rodend of telescope cylinder (check with light and
inspection mirror), seals are defective and require
2-8
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
replacement, or cylinder rod is scored and cylinder
requires overhaul or replacement. If boom has
retracted and oil is leaking from counterbalance
valve, the valve is either improperly adjusted, or
defective and requires replacement.
2.9
CYLINDER CHECKING PROCEDURES
NOTE: Cylinder checks must be performed any time a cylinder component is replaced or when improper system
operation is suspected.
9. Connect hydraulic lines to control valve.
Lift Cylinder
NOTE: Switches referenced in this procedure are located on
the Ground Control Panel.
Cylinder w/o Counterbalance Valves - Steer
Cylinders, Master Level Cylinder, Frame
Jack Cylinders.
1. Activate hydraulic system, properly set extendable
axles and position boom in stowed position; adhere
to all safety precautions.
OPERATE FUNCTIONS FROM GROUND CONTROL STATION
ONLY.
NOTE: Tape measure or cord should be at least 2.1 meters
(7 feet) long for use in this test.
1. Using all applicable safety precautions, activate
engine and fully extend cylinder to be checked. Shut
down engine.
2. Attach tape measure or cord to bottom of platform.
BEFORE RAISING BOOM, ENSURE THAT AREAS ABOVE AND
BELOW BOOM AND PLATFORM ARE CLEAR OF ALL OBSTRUCTIONS AND PERSONNEL.
3. With boom fully retracted, place LIFT control switch
to UP and hold until platform is approximately 6 feet
(2 meters) above ground level. Shut down engine.
4. Tag and carefully disconnect hydraulic lines to lift
cylinder at control valve. Use a suitable container to
retain any residual hydraulic fluid.
5. Observe oil flow from cylinder lines. Oil leaking from
extend port hose indicates a leaking counterbalance
valve. Oil leaking from retract port hose indicates
leakage by cylinder piston.
6. Leave boom elevated in test position for approximately one (1) hour.
7. With tape measure or cord used for reference,
check to see whether boom has lowered (crept)
more than 7.6 cm (3 inches).
8. If boom has lowered and oil is leaking around rodend cap of cylinder, seals in cylinder are defective
and require replacement. If boom has lowered and
oil is leaking from the counterbalance valve, the
valve is either improperly adjusted or defective and
requires replacement.
2. Carefully disconnect hydraulic hose from retract port
of cylinder. There will be initial weeping of hydraulic
fluid which can be caught in a suitable container.
After the initial discharge, there should be no further
leakage from the retract port.
3. Activate engine and activate cylinder extend function. Check retract port for leakage.
4. If cylinder leakage is 6-8 drops per minute or more,
piston seals are defective and must be replaced. If
cylinder retract port leakage is less than 6-8 drops
per minute, carefully reconnect hose to retract port
and retract cylinder.
5. With cylinder fully retracted, shut down engine and
carefully disconnect hydraulic hose from cylinder
extend port.
6. Activate engine and activate cylinder retract function. Check extend port for leakage.
7. If cylinder leakage is 6-8 drops per minute or more,
piston seals are defective and must be replaced. If
extend port leakage is less than 6-8 drops per
minute, carefully reconnect hose to extend port,
then activate cylinder through one complete cycle
and check for leaks.
E N S U R E T H AT H Y D R A U LI C L I N E S A R E C O N N E C TE D A S
MARKED PRIOR TO BEING DISCONNECTED.
9. Connect hydraulic lines to control valve.
3120819
– JLG Lift –
2-9
SECTION 2 - PROCEDURES
Cylinders w/Single Counterbalance Valves Lift Cylinder, Telescope Cylinder, Extend-AReach Cylinder.
Cylinders w/Dual Counterbalance Valve Axle Extension Cylinders, Telescope
Cylinder, Platform Slave Level Cylinder
OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION
ONLY.
OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION
ONLY.
1. Using all applicable safety precautions, activate
hydraulic system.
1. Using all applicable safety precautions, activate
hydraulic system.
WHEN WORKING ON THE LIFT CYLINDER, RAISE THE BOOM TO
HORIZONTAL AND SUPPORT THE BOOM USING A SUITABLE
BOOM PROP OR OVERHEAD LIFTING DEVICE.
2. If working on the telescope cylinder, raise the boom
above horizontal and extend the fly boom approximately 30.5 cm (1 foot). If working on the platform
slave level cylinder, stroke platform level cylinder forward until platform sits at a 45° angle.
2. If working on the lift cylinder, raise boom to horizontal and place a suitable boom prop approximately
2.5 cm (1 inch) below the boom. If working on the
telescope cylinder, raise the boom above horizontal
and extend the fly boom approximately 30.5 cm (1
foot).
3. Shut down hydraulic system and allow machine to
sit for 10-15 minutes. Turn ignition switch to ON,
move control switch or lever for applicable cylinder
in each direction, then turn ignition switch to OFF.
This is done to relieve pressure in the hydraulic
lines. Carefully remove hydraulic hoses from appropriate cylinder port block.
3. Shut down hydraulic system and allow machine to
sit for 10-15 minutes. Turn ignition switch to ON,
move control switch or lever for applicable cylinder
in each direction, then turn ignition switch to OFF.
This is done to relieve excess pressure in the
hydraulic lines. Carefully remove hydraulic hoses
from appropriate cylinder port block.
4. There will be initial weeping of hydraulic fluid which
can be caught in a suitable container. After the initial
discharge, there should not be any further leakage
from the ports. If leakage continues at a rate of 6-8
drops per minute or more, the counterbalance valve
is defective and must be replaced.
4. There will be initial weeping of hydraulic fluid, which
can be caught in a suitable container. After the initial
discharge, there should not be any further leakage
from the ports. If leakage continues at a rate of 6-8
drops per minute or more, cylinder repairs must be
made. If the retract port is leaking, the piston seals
are defective and must be replaced. If the extend
port is leaking, the counterbalance valve is defective
and must be replaced.
5. If no repairs are necessary or when repairs have
been made, carefully reconnect hydraulic hoses to
the appropriate ports.
5. To check piston seals, carefully remove the counterbalance valve from the retract port. After initial discharge, there should not be any further leakage from
the ports. If leakage occurs at a rate of 6-8 drops per
minute or more, the piston seals are defective and
must be replaced.
6. If no repairs are necessary or when repairs have
been made, replace counterbalance valve and carefully reconnect hydraulic hoses to cylinder port
block.
7. Activate hydraulic system and run cylinder through
one complete cycle to check for leaks.
6. If used, remove boom prop or lifting device from
boom, activate hydraulic system and run cylinder
through one complete cycle to check for leaks.
2-10
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
15. Remove the three (3) bolts, washers and lockwashers attaching the chain adjust bracket to the aft end
of the base boom and remove bracket.
2.10 CYLINDER REMOVAL AND
INSTALLATION
16. Pull boom sections apart several feet.
Telescope Cylinder Removal
1. Place machine on a flat and level surface, with axles
extended and the boom fully retracted and in the
horizontal position.
17. Using the lifting equipment, raise the cylinder to
obtain sufficient clearance for removal of the cylinder.
2. Shut down engine. Support boom platform end with
a prop or suitable overhead lifting device.
18. Connect a suitable lifting device to the extension
chain adjust rod on top of the telescope cylinder.
3. Remove boom end cover.
19. Using both lifting devices, carefully pull the cylinder
from the boom assembly.
4. Remove boom length/angle indicator from boom
assembly.
NOTE: The extension rod will come out of the boom twice as
far as the telescope cylinder proportionally.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DISCONNECTING LINES TO AVOID THE ENTRY OF
CONTAMINANTS INTO THE SYSTEM.
20. Continue sliding the cylinder and extension rod out
of the boom until the rod can be separated from the
extension chain by removing the chain clevis attach
pin.
5. Tag and disconnect hydraulic lines to telescope cylinder. Use suitable containers to retain any residual
hydraulic fluid. Cap hydraulic lines and ports.
21. Using the lifting equipment, remove the extension
chain bar.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DISCONNECTING LINES TO AVOID THE ENTRY OF
CONTAMINANTS INTO THE SYSTEM.
6. Tag and disconnect hydraulic lines to telescope cylinder. Use suitable containers to retain any residual
hydraulic fluid. Cap hydraulic lines and ports.
7. Remove the two (2) cotter pins that retain the telescope rod attach pin to the base boom.
22. Continue sliding the cylinder from the boom, laying
the extension chain on top of the base boom as the
cylinder is coming out.
23. Using another lifting device, support the sheave
wheel end of the cylinder and remove the cylinder
from the boom assembly.
24. Carefully lift the cylinder clear of the boom assembly
and lower to the ground or suitably supported work
area.
Telescope Cylinder Installation
8. Using a suitable brass drift, carefully drive the telescope cylinder rod attach pin from the base boom.
9. Remove the telescope cylinder trunnion attach pin
cover from each side of the base boom.
10. Remove the setscrews securing the telescope cylinder attach pin from each side of the telescope cylinder trunnion.
11. Using a suitable slide hammer, remove the half pins
attaching the telescope cylinder to the inner mid
boom section.
12. Attach a suitable sling to the telescope cylinder rod.
Support with an overhead crane or other suitable lifting device.
13. Remove the rod support bracket at the aft end of the
base boom.
14. Remove the two (2) extension chain adjusting nuts
at the aft end of the base boom.
3120819
– JLG Lift –
1. Using suitable lifting equipment, carefully lower the
cylinder to the boom assembly.
2. Using another lifting device, support the sheave
wheel end of the cylinder and install the cylinder into
the boom assembly.
3. Slide the extension cylinder into the boom, sliding
the extension chain in place as the cylinder is moving in.
4. Using the lifting equipment, install the extension
chain bar.
5. Continue sliding the cylinder and extension rod into
the boom until the rod can be attached to the extension chain by installing the chain clevis attach pin.
6. Install the chain adjust bracket and install the three
(3) bolts, washers and lockwashers which attach the
bracket to the aft end of the base boom.
2-11
SECTION 2 - PROCEDURES
7. Install the two (2) extension chain adjusting nuts at
the aft end of the base boom.
Lift Cylinder Removal
1. Place the machine on a flat and level surface. Start
the engine and place the boom in a horizontal position. Shut down the engine and attach a suitable
support device to the boom.
8. Install the rod support bracket at the aft end of the
base boom.
9. Remove the sling attached to the telescope cylinder
rod.
2. Tag, disconnect and cap the lift cylinder hydraulic
lines and ports.
10. Pull boom sections back into the fully retracted position.
3. Remove the bolt, flatwasher and lockwasher securing the cylinder rod attach pin retaining plate to the
boom.
11. Using a suitable brass drift, if necessary, install the
half pins attaching the telescope cylinder to the
inner mid boom section.
4. Remove the two bolts and two lockwashers securing
the pin retaining plate to the pin. Using a suitable
brass drift drive out the cylinder rod attach pin.
12. Install setscrews that attach the telescope cylinder
attach pins to each side of the telescope cylinder
trunnions.
5. Using auxiliary power, retract the lift cylinder rod
completely.
13. Install the telescope cylinder trunnion attach pin
cover to each side of the base boom.
14. Carefully install the telescope cylinder rod attach pin
into the base boom.
6. Remove the barrel end attach pin retaining plate and
hardware. Using a suitable brass drift drive out the
barrel end attach pin from the upright.
15. Install the two (2) cotter pins that retain the telescope rod attach pin to the base boom.
7. Remove the cylinder from the boom and place in a
suitable work area.
16. Remove applicable hydraulic line and port caps and
correctly connect the hydraulic lines to the telescope cylinder. Ensure that all hoses are correctly
routed.
Lift Cylinder Installation
17. Cycle telescope function several times to dissipate
any air from cylinder and lines. Properly torque
boom chains to 80 Nm (59 ft. lb.).
18. Install boom length/angle indicator on boom assembly.
NOTE: Boom length/angle indicator will need to be adjusted
as per the procedure listed in paragraph 2-24 of this
manual.
19. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
20. Install boom end cover.
2. Using a suitable drift, drive the barrel end attach pin
through the mounting holes in the lift cylinder and
the upright. Secure in place with the pin retaining
plate and hardware.
3. Remove cylinder port plugs and hydraulic line caps
and correctly attach lines to cylinder ports.
4. Using auxiliary power, extend the cylinder rod until
the attach pin hole aligns with those in the boom.
Using a suitable drift, drive the cylinder rod attach
pin through the aligned holes, taking care to align
the grooved pin holes. Secure the pin in place with
the bolt, lockwasher and nut.
5. Place boom in the stowed position and shut down
engine. Check hydraulic fluid level and adjust
accordingly.
21. Retract boom fully and place in stowed position.
2-12
1. Install lift cylinder in place using suitable slings or
supports, aligning attach pin mounting holes on the
upright.
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Master Level Cylinder Removal
5. Remove restraining slings from level cylinder.
6. Remove temporary hydraulic lines from cylinder
ports and turntable swing motor hydraulic supply.
Reattach hydraulic supply to swing motor.
1. With the main boom positioned to horizontal and
properly supported, prepare to remove the upright
level cylinder.
7. Remove caps from cylinder hydraulic lines and correctly install lines to cylinder.
2. Remove the bolt, lockwasher and nut securing the
level cylinder rod attach pin to the tower boom.
Using an appropriate brass drift, drive out the level
cylinder rod attach pin.
8. Remove boom support. Place boom in stowed position. Check hydraulic fluid level and adjust accordingly.
3. Tag, disconnect and cap hydraulic lines to level cylinder.
NOTE: When disconnecting hydraulic lines, any residual
hydraulic fluid should be drained into a suitable container.
4. Make up two temporary hose assemblies (3/8 In. x
10 ft.) to carry power from the turntable swing motor
supply hoses to the lift cylinder. Couple temporary
hoses to swing motor supply hoses, using reducer
fittings if necessary. Plug ports in swing motor.
5. After installing temporary hoses, activate swing function, using auxiliary power, to fully retract level cylinder rod.
2.11 CYLINDER REPAIR
NOTE: The following are general procedures that apply to
all of the cylinders on this machine. Procedures that
apply to a specific cylinder will be so noted.
Disassembly
DISASSEMBLY OF THE CYLINDER SHOULD BE PERFORMED ON
A CLEAN WORK SURFACE IN A DIRT FREE WORK AREA.
1. Connect a suitable auxiliary hydraulic power source
to the cylinder port block fitting.
6. Remove temporary hoses from level cylinder and
cap them. Plug cylinder ports.
7. Using slings, restrain level cylinder.
8. Remove retaining plate and bolts from upright cylinder attach pin.
DO NOT FU LLY EXTEN D CYLINDER TO END OF STROKE.
RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRESSURE.
9. Using an appropriate brass drift, drive out the
upright attach pin. Carefully remove restraining
slings and remove level cylinder from boom.
2. Operate the hydraulic power source and extend the
cylinder. Shut down and disconnect the power
source. Adequately support the cylinder rod, if applicable.
Master Level Cylinder Installation
1. With the boom positioned at horizontal and properly
supported, place the master level cylinder in position on the boom and secure in place using slings.
2. Align barrel end bushing with pin attach blocks in
turntable upright and install upright attach pin using
appropriate brass drift. Secure pin with retaining
plate and retaining plate bolts.
FOR CYLINDERS WITH DOUBLE HOLDING VALVES, CRACK
BLEEDERS TO RELEASE PRESSURE BEFORE REMOVING HOLDING VALVES.
3. Remove caps from temporary hydraulic lines and
attach to level cylinder ports. Using auxiliary power,
activate swing function and extend cylinder rod until
rod bushing aligns with boom lift cylinder rod end
attach bushing.
4. Using an appropriate brass drift drive the rod attach
pin through the aligned bushings of the cylinder rod
and boom lift cylinder rod end attach plate, taking
care to align holes for bolt attachment. Secure rod
end attach pin with bolt, lockwasher and nut.
3120819
– JLG Lift –
2-13
SECTION 2 - PROCEDURES
ROD SUPPORT
ROD SUPPORT
3. If applicable, remove the cartridge-type holding
valve and fittings from the cylinder port block. Discard o-rings.
BARREL CLAMP
PROTECTED
ROD CLAMP
PROTECTED
ROD CLAMP
SUPPORT
TABLE
SUPPORT
TABLE
Figure 2-4. Cylinder Rod Support
Figure 2-3. Cylinder Barrel Support
8. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
as possible.
4. Place the cylinder barrel into a suitable holding fixture. Tap around outside of cylinder head retainer
with a suitable hammer to shatter loctite.
9. Remove the set screw(s), if applicable, and nut
which attach the piston to the rod, and remove the
piston. Discard nylon point set screws.
5. Using a suitable spanner wrench, loosen the cylinder head retainer, if applicable, and/or cylinder head
gland, and remove from cylinder barrel.
6. Attach a suitable pulling device to the cylinder rod
port block end or cylinder rod end, as applicable.
EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYLINDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFFCENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
CYLINDER BARREL SURFACES.
7. With the barrel clamped securely, apply pressure to
the rod pulling device and carefully withdraw the
complete rod assembly from the cylinder barrel.
10. Remove the piston rings.
11. Remove and discard the piston o-rings, seal rings,
and backup rings.
12. Remove the set screw, if applicable, piston spacer,
and wear ring, if applicable, from the rod.
13. Remove the rod from the holding fixture. Remove
the cylinder head gland and retainer, if applicable.
Discard the o-rings, back-up rings, rod seals, and
wiper seals.
Cleaning and Inspection
ONCE THE HEAD GLAND HAS CLEARED THE CYLINDER CASE
MOUTH, THE ROD MUST BE SUPPORTED CLOSE TO THE CYLINDER CASE PRIOR TO THE PISTON BEING PULLED PAST THE
CYLINDER CASE THREADS. THIS IS DONE TO AVOID DAMAGE
TO THE CYLINDER CASE THREADS, AND/OR THE PISTON AND
PISTON SEALS.
1. Clean all parts thoroughly in an approved cleaning
solvent.
2. Inspect the cylinder rod for scoring, tapering, ovality,
or other damage. If necessary, dress rod with
Scotch Brite or equivalent. Replace rod if necessary.
3. Inspect threaded portion of rod for excessive damage. Dress threads as necessary.
4. Inspect inner surface of cylinder barrel tube for scoring or other damage. Check inside diameter for
tapering or ovality. Replace if necessary.
5. Inspect threaded portion of barrel for damage. Dress
threads as necessary.
2-14
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
6. Inspect piston surface for damage and scoring and
for distortion. Dress piston surface or replace piston
as necessary.
7. Inspect seal and o-ring grooves in piston for burrs
and sharp edges. Dress applicable surfaces as necessary.
8. Inspect cylinder head inside diameter for scoring or
other damage and for ovality and tapering. Replace
as necessary.
9. Inspect seal and o-ring grooves in head for burrs
and sharp edges. Dress applicable surfaces as necessary.
10. If applicable, inspect cylinder head retainer or end
cap for surface or thread damage. Repair or replace
as necessary.
Assembly
NOTE: Prior to cylinder assembly, ensure that the proper
cylinder seal kit is used. See your JLG Parts Manual.
NOTE: Apply a light film of hydraulic oil to all components
prior to assembly.
WHEN INSTALLING NEW “POLY-PAK” TYPE PISTON SEALS,
ENSURE SEALS ARE INSTALLED PROPERLY. REFER TO FIGURE
2-1 FOR CORRECT SEAL ORIENTATION. IMPROPER SEAL
INSTALLATION COULD RESULT IN CYLINDER LEAKAGE AND
IMPROPER CYLINDER OPERATION.
11. Inspect cylinder head outside diameter for scoring
or other damage and ovality and tapering. Replace
as necessary.
12. If applicable, inspect thread ring for scoring or other
damage. Dress threads or applicable surfaces as
necessary.
13. If applicable, inspect rod and barrel bushings for
signs of correct lubrication and excessive wear.
Replace as necessary.
Figure 2-5. Poly-Pak Seal Installation
14. Inspect travel limiting collar or spacer for burrs and
sharp edges. If necessary, dress inside diameter
surface with Scotch Brite or equivalent.
1. Place a new wiper seal and rod seal into the applicable cylinder head gland grooves.
2. Carefully install the head gland on the rod, ensuring
that the wiper and rod seals are not damaged or dislodged. Push the head along the rod to the rod end,
as applicable.
15. If applicable, inspect port block fittings and holding
valve. Replace as necessary.
16. Inspect the oil ports for blockage or the presence of
dirt or other foreign material. Repair as necessary.
3. Carefully slide the piston spacer on the rod. If applicable, align the oil holes in the rod and the spacer.
Secure the spacer, if applicable.
17. If applicable, inspect piston rings for cracks or other
damage. Replace as necessary.
4. If applicable, correctly place a new o-ring and backup rings in the inner piston diameter groove.
5. Carefully place the piston on the cylinder rod, ensuring that the o-ring and back-up rings are not damaged or dislodged.
6. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
as possible.
7. Push the piston onto the rod until it abuts the spacer
end and install the attaching nut.
IF CYLINDER IS EQUIPPED WITH A PISTON NUT, APPLY “LOCQUIC PRIMER T” AND LOCTITE #242 TO PISTON NUT THREADS,
THEN TIGHTEN NUT TO TORQUE SHOWN IN TABLE 2-2.
3120819
– JLG Lift –
2-15
SECTION 2 - PROCEDURES
NOTE: Self-locking setscrews used on piston nuts should be
discarded and replaced whenever they are removed.
Table 2-2. Cylinder Piston Nut Torque Specifications
14. If applicable, secure the cylinder head retainer using
a suitable spanner type wrench in the holes provided.
15. After the cylinder has been reassembled, the rod
should be pushed all the way in (fully retracted) prior
to the reinstallation of any holding valve or valves.
Nut Torque
Value (w/Loctite)
Setscrew
Torque Value (w/
Loctite)
Axle Extension
Cylinder
542 Nm (400 ft.
lb.)
11 Nm (100 in.
lb.)
Extend-a-Reach
Cylinder
542 Nm (400 ft.
lb. )
11 Nm (100 in.
lb.)
Frame Jack
Cylinder
542 Nm (400 ft.
lb.)
11 Nm (100 in.
lb.)
Level/Slave
Cylinder
271 Nm (200 ft.
lb.)
11 Nm
(100 in. lb.)
Lift Cylinder
813 Nm (600 ft.
lb.)
22 Nm (200 in.
lb.)
108 Nm (80 ft. lb.)
11 Nm (100 in.
lb.)
Sun - 7/8 hex M20 x 1.5 thds
11 Nm (100 in.
lb.)
41-48 Nm
(30-35 ft. lb.)
Sun - 1-1/8 hex 1-14 UNS thds
22 Nm (200 in.
lb.)
61-68 Nm
(45-50 ft. lb.)
Sun - 1-1/4 hex M36 x 2 thds
Description
Master Cylinder
Steer Cylinder
Telescope
Cylinder
108 Nm (80 ft. lb.)
813 Nm (600 ft.
lb.)
16. If applicable, install the cartridge-type holding valve
and fittings in the rod port block using new o-rings
as applicable.
IF THE CYLINDER IS TO BE TESTED PRIOR TO INSTALLATION ON
THE MACHINE, EXTREME CARE SHOULD BE USED TO INSURE
THAT THE OUTER END OF THE ROD IS SUPPORTED. USE
EITHER A TRAVELING OVERHEAD HOIST, FORKLIFT, OR OTHER
MEANS TO SUPPORT THE OVERHANGING WEIGHT OF THE
EXTENDING ROD.
Table 2-3. Holding Valve Torque Specifications
Description
Torque Value
204-217 Nm
(150-160 ft. lb.)
8. If applicable, install the setscrew(s) which secure the
piston attaching nut to the diameter groove.
Racine - 1-1/8 hex 1-1/16 - 12 thds
68-75 Nm
(50-55 ft. lb.)
9. Remove the cylinder rod from the holding fixture.
Racine - 1-3/8 hex 1-3/16 - 12 thds
102-109 Nm
(75-80 ft. lb.)
Racine - 1-7/8 hex 1-5/8 - 12 thds
136-149 Nm
(100-110 ft. lb.)
10. Place new o-rings and seals in the applicable outside diameter grooves of both the piston and the cylinder head.
11. Position the cylinder barrel in a suitable holding fixture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE
CYLINDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD
OFF-CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON
AND CYLINDER BARREL SURFACES.
12. With barrel clamped securely, and while adequately
supporting the rod, insert the piston end into the
barrel cylinder. Ensure that the piston loading o-ring
and seal ring are not damaged or dislodged.
13. Continue pushing the rod into the barrel until the cylinder head gland can be inserted into the barrel cylinder or, if applicable, until the cylinder head threads
engage the threads of the barrel.
2-16
NOTE: Steps (17) through (20) apply to the telescope cylinder.
17. Elevate the barrel end of the cylinder to a work
bench or other suitable device.
18. Plug the retract port and supply hydraulic power to
the extend port.
19. Open the bleeder port plug (TP), venting all trapped
air to atmosphere. Retighten the bleeder port plug.
Disconnect the hydraulic power source and remove
plug from retract port.
20. An alternative to steps (18) through (20) is to position the barrel horizontally in a suitable holding
device, attach a hydraulic power source to both
extend and retract ports, while supporting the cylinder rod, cycle the cylinder a minimum of 5 times with
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
the bleeder port unplugged, venting all trapped air
to atmosphere. A suitable hose may be attached to
the bleeder port with the end in a container suitable
to contain the hydraulic fluid. After all air is vented
remove all attached hoses, and install the bleeder
port plug. Also plug the extend and retract ports until
cylinder is installed in boom.
1. Loosen the right side powertrack bracket and powertrack and lay on top of boom assembly.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
2. Tag and disconnect hydraulic lines to slave level cylinder and rotator motor.
2.12 BOOM MAINTENANCE
Removal
3. Tag and disconnect wiring to platform control box.
4. Remove the left side powertrack.
1. Shut down machine systems.
5. Remove platform from boom assembly.
NOTE: Boom Assembly, less extend-a-reach and jib, weighs
approximately 4309 kg (9,500 lb.).
6. Remove cotter pins retaining telescope cylinder rod
attach pin to base section.
2. Using suitable lifting equipment, adequately support
boom weight along entire length of retracted boom.
7. Using a suitable brass drift, carefully drive telescope
cylinder pin from base section.
8. Remove outer mid section extend chain adjust nut
and locknut at upper aft end of base section.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
3. Tag and disconnect hydraulic lines that run along
the side of the boom.
4. Remove hardware attaching upper lift cylinder
attach pin to boom.
5. Using a slide hammer or similar tool, and taking care
not to damage pin, remove pin from boom.
6. Using all applicable safety precautions, and only if
necessary, operate crane and fully retract lift cylinder.
7. Shut down machine systems.
8. Tag and disconnect all wiring to ground control box.
9. Remove boom length/angle indicator box.
10. Loosen and remove hardware securing boom pivot
pin.
11. Ensuring that boom is adequately supported and
using a suitable slide hammer, carefully remove
pivot pin from boom and turntable structure. Ensure
that boom and turntable structure are not damaged.
9. Remove bolts, washers and lockwashers attaching
outer mid section extend chain attach block to upper
aft end of base section. Remove block.
10. Remove fly section extend chain adjust nut and
locknut at lower front end of inner mid section.
11. Remove outer mid section retract chain adjust nut
and locknut at lower front end of base section.
12. Remove fly section retract chain adjust nut and locknut at lower front end of inner mid section.
NOTE: Note and record the number and thickness of any
wear pad shims during wear pad removal.
13. Remove bolts and lockwashers attaching side wear
pads to front of base section. Remove pads and any
shims.
14. Remove bolts, washers and lockwashers attaching
lower front wear pads and mounting blocks to base
section. While supporting assembled fly, outer mid
and inner mid sections, remove wear pads, mounting blocks and shims.
15. Remove bolts and lockwashers attaching top front
wear pad to base section. Remove pad and shims.
12. Carefully lift boom assembly clear of turntable and
lower to ground or suitably supported work surface.
16. Using suitable lifting equipment, partially slide
assembled inner mid, outer mid and fly sections out
of base section.
Disassembly
17. Using suitable straps, tie off outer mid section retract
chains to underside of inner mid section as inner
mid, outer mid and fly sections are exiting base section.
NOTE: Left or right is determined facing the machine from
the platform.
3120819
– JLG Lift –
2-17
SECTION 2 - PROCEDURES
16
12
17
16
5
16
14
6
Figure 2-6. Boom Assembly - Sheet 1 of 2
2-18
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
1.
2.
3.
4.
5.
6.
7.
8.
9.
Boom Base
Inner Mid Boom
Outer Mid Boom
Fly Boom
Telescope Cylinder
Outer Mid Extend Chain
Fly Extend Chain
Fly Retract Chain
Outer Mid Retract Chain
10.
11.
12.
13.
14.
15.
16.
17.
18.
Tele Cylinder Sheave
Sheave
Chain Extend Rod
Chain Attach Pin
Chain Adjustment Assembly
Chain Adjustment Assembly
Upper Rear Wear Pad
Adjustment & Jam Nuts
Safety Chain
13
10
1
18
2
3
4
8
7
18
9
15
15
11
Figure 2-7. Boom Assembly - Sheet 2 of 2
3120819
– JLG Lift –
2-19
SECTION 2 - PROCEDURES
18. Carefully lift inner mid, outer mid and fly sections
clear of base section and lower to a suitably supported work area.
19. Using suitable lifting equipment, support telescope
cylinder rod.
20. Remove setscrew securing trunnion pins that secure
inner mid section to telescope cylinder.
21. Using a suitable tool, scribe a line on the outer end
of each trunnion pin and boom structure as an aid to
pin alignment during boom assembly.
22. Using a suitable slide hammer, remove trunnion pins
attaching telescope cylinder to inner mid section.
23. Remove cotter pins and chain attach pins attaching
outer mid section retract chains to lower aft end of
outer mid section and remove chains.
24. Remove setscrews which attach chain sheave pins
at lower aft end of inner mid section.
25. Using a suitable brass drift, carefully drive sheave
pins from inner mid section and remove sheaves
and thrust washers. If necessary, remove bushings
from sheaves and replace. Ensure that pins, grease
fittings and corresponding boom and sheave surfaces are not damaged.
26. Remove cotter pins and chain attach pins attaching
fly section retract chains to lower aft end of fly section and remove chains.
27. Remove setscrews which attach chain sheave pins
at lower aft end of outer mid section.
28. Using a suitable brass drift, carefully drive sheave
pins from outer mid section and remove sheaves,
seals, and thrustwashers. If necessary, remove
bushings from sheaves and replace. Ensure that
pins, grease fittings and corresponding boom and
sheave surfaces are not damaged.
29. Pull boom sections out several feet to allow ample
clearance for telescope cylinder removal.
30. Remove outer mid section extension chain adjust
nut and locknut from clevis at lower aft end of outer
mid section.
31. Using suitable lifting equipment, carefully slide telescope cylinder out of fly, outer mid, and inner mid
sections, along with extension chain and bar.
32. When approximately one-half of the telescope cylinder is removed from the boom assembly, the extension bar attach to chain will become accessible.
Remove cotter pins and clevis pin attaching extension bar to chain and remove bar.
33. Carefully lift telescope cylinder clear of boom
assembly and lower to ground or suitably supported
work area.
2-20
34. Remove bolts attaching outer mid section retract
chain adjust block at lower front end of inner mid
section and remove block.
NOTE: Note and record number and thickness of any wear
pad shims during wear pad removal.
35. Remove bolts and lockwashers which attach upper
aft inner mid section wear pads and remove pads
and any shims.
36. Remove bolts, washers and lockwashers which
attach bottom wear pads at front of inner mid section and remove pads and any shims.
37. Remove bolts and lockwashers which attach side
wear pads at front of inner mid section and remove
pads and any shims.
38. Remove bolts and lockwashers which attach top
wear pad at front of inner mid section and remove
pad and any shims.
39. Using suitable lifting equipment, carefully slide outer
mid and fly sections clear of inner mid section and
lower to ground or other suitably supported work
area.
40. Remove bolts and lockwashers which attach upper
aft outer mid section wear pads and remove pads
and any shims.
41. Remove bolts and lockwashers which attach bottom
wear pads at front of outer mid section and remove
pads and any shims.
42. Remove bolts and lockwashers which attach side
wear pads at front of outer mid section and remove
pads and any shims.
43. Remove bolts and lockwashers which attach top
wear pads to front of outer mid section and remove
pads and any shims.
44. Remove bolt, washer and lockwasher attaching fly
section right hand extend chain sheave attach pin to
front of outer mid section.
45. Using a suitable brass drift, carefully drive each
sheave pin from the boom section and remove the
sheave assemblies. Inspect pins, lubrication fittings
and sheave bearings for damage and dirt or foreign
material. Replace components as necessary.
46. Repeat steps (42) and (43) for left hand sheave.
47. Using suitable lifting equipment, carefully slide fly
section clear of outer mid section and lower to
ground or suitably supported work area.
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Inspection
1. Inspect all sheaves (extend chains, retract chains
and telescope cylinder) for excessive groove wear,
burrs or other damage. Replace sheaves as necessary.
2. Inspect extend chain and retract chain sheave bearings for wear, scoring, or other damage, and for
ovality. Replace bearings as necessary, ensuring
they are installed flush with sheave surface.
3. Inspect extend chain and retract chain sheave pins
for scoring, tapering, ovality and evidence of correct
lubrication. Replace pins as necessary.
13. Inspect all threaded components for damage such
as stretching, thread deformation, or twisting.
Replace as necessary.
14. Inspect structural units of boom assembly for bending, cracking, separation of welds, or other damage.
Replace boom sections as necessary.
Assembly
NOTE: When installing fly section wear pads, install same
number and thickness of shims as were removed
during disassembly.
1. Install upper aft fly section wear pads and shims, as
required, using bolts and lockwashers.
4. Inspect telescope cylinder sheave pin for tapering,
scoring, ovality and evidence of correct lubrication.
Replace pin as necessary.
2. Using suitable lifting equipment, carefully slide fly
section into outer mid section.
3. Install fly section extend chain sheaves on front of
outer mid section and install sheave pins.
5. Inspect boom pivot pin for wear, scoring or other
damage, and for tapering or ovality. Replace pin as
necessary.
6. Inspect upper lift cylinder attach pin for tapering,
ovality, scoring, wear, or other damage. Ensure pin
surfaces are protected prior to installation. Replace
pin as necessary.
4. Install lubrication fittings in ends of pins and lubricate sheaves with MPG.
NOTE: When installing outer mid section wear pads, install
same number and thickness of shims, as required,
using bolts and lockwashers.
5. Install outer mid section top front wear pads and
shims, as required, using bolts and lockwashers.
7. Inspect telescope cylinder trunnion attach pin for
tapering, ovality, scoring, wear, or other damage.
Replace pin as necessary.
6. Install outer mid section side front wear pads and
shims, as required, using bolts and lockwashers.
8. Inspect extend chain attach clevis pins for wear,
scoring, or other damage. Replace pins as necessary.
7. Install outer mid section bottom front wear pads and
shims, as required, using bolts and lockwashers.
8. Install outer mid section upper aft wear pads and
shims, as required, using bolts and lockwashers.
9. Inspect telescope cylinder rod attach pin for scoring,
wear, or other damage. Replace pin as necessary.
9. Using suitable lifting equipment, carefully slide
assembled outer mid and fly sections into inner mid
section.
10. Inspect inner diameter of boom pivot bushing for
scoring, distortion, wear, or other damage. Replace
bushing as necessary.
11. Inspect all wear pads for excessive wear or damage.
Replace pads when worn to within 1/8 inch (3.2 mm)
of insert.
12. Inspect extend and retract chains and chain attach
component for cracks, stretching, distortion, or
other damage. Replace components as necessary.
3120819
NOTE: When installing inner mid section wear pads, install
same number and thickness of shims as were
removed during disassembly.
10. Install inner mid section top front wear pads and
shims, as required, using bolts and lockwashers.
– JLG Lift –
2-21
SECTION 2 - PROCEDURES
11. Install inner mid section side front wear pads and
shims, as required, using bolts and lockwashers.
12. Install inner mid section bottom front wear pads and
shims, as required, using bolts, washers and lockwashers.
13. Install inner mid section upper aft wear pads and
shims, as required, using bolts and lockwashers.
14. Install fly section retract chain adjust block on lower
front end of inner mid section and secure with bolts.
15. Place outer mid section extend chain assembly
along telescope cylinder chain rest with chain adjust
assembly hanging just below cylinder sheave.
16. Using lightweight motor oil (SAE 20W), adequately
lubricate portion of chain occupying cylinder chain
rest.
17. Using suitable lifting equipment, maneuver telescope cylinder and outer mid section extend chain
assembly into position at aft end of assembled
boom sections.
18. With a slight downward angle on the cylinder, insert
sheave and chain adjust into boom sections until it
is possible to insert chain adjust into attach block at
rear of outer mid section. Temporarily install chain
adjust and locknuts.
19. Carefully feed telescope cylinder approximately halfway into boom sections, lubricating chain with lightweight motor oil as it passes along chain rest. Attach
extension bar to chain and continue inserting into
boom sections.
20. Install fly section retract chain sheaves, seals and
thrustwashers at aft end of outer mid section.
21. Install sheave pins and if necessary, tap pins into
place using a soft headed mallet. Secure pins with
setscrews.
22. Install lubrication fittings on ends of pins and lubricate sheaves with MPG.
23. Install fly section retract chains at lower aft end of fly
section. Install chain attach pins and flatwashers and
secure with cotter pins.
24. Carefully place fly section retract chains around
chain sheaves at aft end of inner mid section and
through bottom of inner mid section.
25. Install fly section retract chain clevis into attach
block at lower front end of inner mid section. Install
adjust nut and locknut on clevis.
26. Install outer mid section retract chain sheaves and
thrust washers at aft end of inner mid section.
27. Install sheave pins and, if necessary, tap pins into
place using a soft headed mallet. Secure pins with
setscrews.
28. Install lubrication fittings on ends of pins and lubricate sheaves with MPG.
29. Install outer mid section retract chains at lower aft
end of outer mid section. Install chain attach pins
and flatwashers and secure with cotter pins.
30. Carefully place outer mid section retract chains
around chain sheaves at aft end of inner mid section. Tie chains to underside of inner mid section
using suitable straps.
31. Using suitable lifting equipment, carefully align holes
in telescope cylinder trunnion and holes in aft end of
inner mid section.
32. Install trunnion pins, ensuring that holes in pins align
with holes in trunnion. If necessary, tap pins into
place with a soft headed mallet. Secure pins with
setscrews.
33. Using suitable lifting equipment, carefully slide
assembled inner mid, outer mid, and fly sections
into base section.
34. As sections are being installed, remove straps from
outer mid section retract chains and feed attach clevis through holes in bottom of forward end of base
section.
35. Install outer mid section retract chain clevis into
attach block at lower front end of base boom section. Install adjust nut and locknut on clevis.
NOTE: When installing base section wear pads, install same
number and thickness of shims as were removed
during disassembly.
36. Install base section top front wear pads and shims,
as required, using bolts and lockwashers.
37. Install base section lower front wear pads, mounting
blocks, and shims, as required, using bolts, washers, and lockwashers.
2-22
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
38. Install base section side front wear pads and shims,
as required, using bolts and lockwashers.
6. If necessary, gently tap pin into position with a soft
headed mallet, ensuring that pin plate holes are
aligned with attach holes in boom structure. Install
pin attaching bolts, washers and lockwashers.
39. Carefully align telescope cylinder rod end with holes
in aft end of base boom section and install attach
pin. If necessary, tap pin into place using a soft
headed mallet. Secure pin with cotter pins.
7. Shut down machine systems.
8. Connect hydraulic lines running along side of boom.
40. Install outer mid section extend chain attach block at
aft end of base section and secure with bolts and
lockwashers.
41. Install outer mid section extend chain clevis through
hole in attach block and secure with adjust nut and
locknut.
42. Attach platform to boom assembly.
43. Attach the left side powertrack to boom assembly.
44. Connect wiring to consolette box.
45. Connect hydraulic lines to slave level cylinder and
rotator motor.
9. Install boom length/angle sensor box. Adjust boom
length/angle sensor box in accordance with paragraph 2-26.
10. Using all applicable safety precautions, operate
machine systems and raise and extend boom fully,
noting the performance of the extension cycle. If
chattering is apparent, extend chain system requires
adjustment.
11. Retract and lower boom, noting performance of
retraction cycle. If chattering is apparent, retract
chain system requires adjustment.
12. Shut down machine systems.
46. Attach the right side powertrack bracket and powertrack to boom assembly.
13. Adjust extend and retract chain systems as required
and secure adjustment locknuts.
Installation
14. As necessary, lubricate all points requiring lubrication.
1. Using suitable lifting equipment, position assembled
boom on turntable so that boom pivot holes in both
boom and turntable are aligned.
2. Insert boom pivot pin, ensuring that locating slots in
pin are aligned with setscrew locating holes in pin
bushings.
3. If necessary, gently tap pin into position with a soft
headed mallet. Secure pin with setscrews.
4. Connect all wiring to ground control box.
5. Using all applicable safety precautions, operate lifting equipment in order to position boom lift cylinder
so that holes in cylinder rod end and boom structure
are aligned. Insert lift cylinder pin.
3120819
– JLG Lift –
2-23
SECTION 2 - PROCEDURES
RED
WHITE
BLACK
YELLOW
Figure 2-8. Tilt Switch Adjustment - Voltmeter
3. With the electrical connections complete, slowly
tighten one of the “Y” nuts until the circuit is closed
and the light on the Platform Control Console illuminates.
2.13 TILT ALARM SWITCH
PERFORM TILT ALARM SWITCH LEVELING PROCEDURE A MINIMUM OF EVERY SIX MONTHS TO ENSURE PROPER OPERATION
AND ADJUSTMENT OF SWITCH.
NOTE: Each machine is equipped with a tilt alarm switch
(sensor). The switch is factory set to activate at 5
degrees and will illuminate a warning light and sound
a warning horn. In addition, if the boom is above horizontal when the switch is activated, LIFT and
SWING will go to creep speed. Consult factory for tilt
sensor adjustment. The only field adjustment necessary is leveling the switch on the spring loaded
studs. There are two methods of adjustment, a manual adjustment and an adjustment using a voltmeter.
X
Y
Y
Figure 2-9. Tilt Switch Adjustment - Manual
Manual Adjustment
1. Park the machine on a flat, level surface. Ensure
machine is level and tires are filled to rated pressure.
NOTE: Ensure switch mounting bracket is level and securely
attached.
2. Level the base of the indicator by tightening the
three flange nuts. Tighten each nut through approximately one half of it’s spring’s travel. DO NOT
ADJUST THE “X” NUT DURING THE REMAINDER
OF THE PROCEDURE.
2-24
– JLG Lift –
4. Slowly back off the nut, counting the number of
turns, until the circuit is again closed and the light
again illuminates.
5. Divide the number of turns determined in step (4) in
half. Tighten the nut this many turns. The line determined by this nut and the “X” nut is now parallel to
the ground.
6. Repeat steps (3) through (5) for the remaining “Y”
nut. The switch is now level.
7. Individually push down on one corner at a time;
there should be enough travel to cause the switch to
trip. If the switch does not trip in all three tests, the
3120819
SECTION 2 - PROCEDURES
flange nuts have been tightened too far. Loosen the
“X” nut and repeat steps (3) through (7).
2. Start the engine from ground controls and allow to
come up to operating temperature. Inside the
ground control terminal box, attach a “hot” wire from
the 12 Volt power (red) wire at the PLATFORM/
GROUND SELECT switch to terminal 1 (brown/black
wire) on the relay circuit card at the top of the
ground control terminal box. This will cause the
engine to run as if HIGH ENGINE and HIGH DRIVE
are activated. Adjust slide pin to contact high engine
limit switch at 2500 RPM. Remove “hot” wire from
terminal 1 and from PLATFORM/GROUND SELECT
switch. Shut down engine.
Voltmeter Adjustment
1. Park machine on a flat, level surface. Ensure
machine is level and tires are filled to rated pressure.
2. If engine is not running, turn ignition switch to ON.
3. Connect black lead of voltmeter to ground and red
lead to yellow wire protruding from pot on bottom of
sensor.
4. Adjust leveling nuts to obtain the highest possible
voltage reading.
NOTE: Actuator cable travel must stop slightly before lever
makes contact with throttle lever stop. Failure to do
so will burn out actuator.
5. Check voltage at trip point in all four directions. If
voltage reading is not symmetrical, repeat step (4)
above.
2.16 PRESSURE SETTING PROCEDURES
Main Valve
2.14 LIMIT SWITCH ADJUSTMENTS
1. Main Relief.
Boom Limit Switch
The boom limit switch is located on the left side of the
base section of the boom. The switch will activate when
the boom is extended past a set point with the axles
retracted. When activated, the switch cuts out Telescope
Out and Lift Up. Adjust the limit switch to trip at 10 feet (3
meters) of boom extension.
a. Plug pressure gauge into quick-connect on main
valve. Monitor gauge.
b. Bottom out Lift Up function.
c. Loosen nut at main relief and adjust pressure to
238 bar (3450 psi) using an Allen wrench.
Tighten nut.
2. Lift Down Relief.
Horizontal Cut-Out Switch
The horizontal cut-out switch is located on the right side of
the boom at the boom pivot pin. When activated, the
switch cuts out the High Engine, High Drive and 2 Speed
functions. Adjust the switch to activate when the boom
reaches horizontal.
a. Monitor pressure gauge at quick-connect on
main valve.
b. Bottom out Lift Down function.
c. Loosen nut at lift down relief and adjust pressure
to 83 bar (1200 psi) using an Allen wrench.
Tighten nut.
3. Swing Relief.
2.15 THROTTLE CHECKS AND
ADJUSTMENTS - DEUTZ ENGINE
a. Monitor pressure gauge at quick-connect on
main valve.
NOTE: Never run fuel tank dry. Diesel engines cannot be
restarted after running out of fuel until fuel system
has been air-vented or “bled” of air. See Deutz
instruction manual for procedure.
1. Disconnect actuator cable from throttle lever. With
the aid of an assistant, start the engine and allow it
to come up to operating temperature. Adjust throttle
lever stop until engine runs at 1800 RPM. Shut down
engine. Reattach actuator cable to throttle lever,
making sure that low (mid) engine setting remains
the same. If necessary, adjust slide pin to contact
low (mid) engine limit switch at 1800 RPM. Shut
down engine.
3120819
– JLG Lift –
b. Ensure turntable lock is engaged.
c. Bottom out Swing Right function.
d. Loosen nut at swing right relief and adjust pressure to 83 bar (1200 psi) using an Allen wrench.
Tighten nut.
e. Bottom out Swing Left function.
f. Loosen nut at swing left relief and adjust pressure to 83 bar (1200 psi) using an Allen wrench.
Tighten nut.
4. Extend-A-Reach Relief.
a. Monitor pressure gauge at quick-connect on
main valve.
2-25
SECTION 2 - PROCEDURES
ACTUATOR CABLE
THROTTLE LEVER
INJECTION PUMP
THROTTLE LEVER STOP
ADECO ACTUATOR
ADECO ACTUATOR
ACTUATOR CABLE
SLIDE PIN (1)
LIMIT SWITCH
HIGH ENGINE LIMIT SWITCH
LOW ENGINE
SLIDE PIN (2)
Figure 2-10. Throttle Checks and Adjustments - Deutz Engine
2-26
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
2. Axle Extension/Retraction Relief.
b. Bottom out Extend-A-Reach Up function.
c. Loosen nut at extend-a-reach up relief and
adjust pressure to 207 bar (3000 psi) using an
Allen wrench. Tighten nut.
d. Bottom out Extend-A-Reach Down function.
e. Loosen nut at extend-a-reach down relief and
adjust pressure to 97 bar (1400 psi) using an
Allen wrench. Tighten nut.
5. Platform Rotate Relief.
a. Monitor pressure gauge at quick-connect on
frame valve.
b. Raise front end of machine using front frame
jack.
c. Bottom out Front Axle Extend function.
d. Loosen nut on front axle extend relief and adjust
pressure to 138 bar (2000 psi). Tighten nut.
e. Bottom out Front Axle Retract function.
a. Monitor pressure gauge at quick-connect on
main valve.
f. Loosen nut on front axle retract relief and adjust
pressure to 152 bar (2200 psi). Tighten nut.
b. Bottom out Rotate Right function.
g. Lower front end of machine.
c. Loosen nut on rotate right relief and adjust pressure to 172 bar (2500 psi). Tighten nut.
h. Raise rear end of machine using rear frame jack.
d. Bottom out Rotate Left function.
j. Loosen nut on rear axle extend relief and adjust
pressure to 138 bar (2000 psi). Tighten nut.
e. Loosen nut on rotate left relief and adjust pressure to 172 bar (2500 psi). Tighten nut.
i. Bottom out Rear Axle Extend function.
6. Platform Level Relief.
a. Monitor pressure gauge at quick-connect on
main valve.
b. Bottom out Platform Level Up function.
c. Loosen nut on platform level up relief and adjust
to . Tighten nut.
d. Bottom out Platform Level Down function 172
bar (2500 psi). Tighten nut.
e. Loosen nut on platform level down relief and
adjust to 138 bar (2000 psi).
Frame Valve
1. Steer Relief.
NOTE: Torque frame valve bolts to 9 Nm (80 in. lb.) after
checking or adjusting adjusting steer pressure.
a. Plug pressure gauge into quick-connection on
frame valve. Monitor gauge.
b. Bottom out Front Steer Right function.
c. Loosen nut on front steer right relief and adjust
to 138 bar (2000 psi). Tighten nut.
d. Bottom out Front Steer Left function.
e. Loosen nut on front steer left relief and adjust to
138 bar (2000 psi). Tighten nut.
f. Bottom out Rear Steer Right function.
g. Loosen nut on rear steer right relief and adjust to
138 bar (2000 psi). Tighten nut.
h. Bottom out Rear Steer Left function.
i. Loosen nut on rear steer left relief and adjust to
138 bar (2000 psi). Tighten nut.
3120819
– JLG Lift –
2-27
SECTION 2 - PROCEDURES
Figure 2-11. Pressure Setting Adjustments - Main Valve - Machines Built Before S/N 38697
2-28
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Figure 2-12. Pressure Setting Adjustments - Frame Valve - Machines Built Before S/N 38697
3120819
– JLG Lift –
2-29
SECTION 2 - PROCEDURES
Figure 2-13. Pressure Setting Adjustments - Main Valve - Machines Built After S/N 38697
2-30
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Figure 2-14. Pressure Setting Adjustments - Frame Valve - Machines Built After S/N 38697
3120819
– JLG Lift –
2-31
SECTION 2 - PROCEDURES
k. Bottom out Rear Axle Retract function.
Check the turntable to bearing. Attach bolts as follows:
l. Loosen nut on rear axle retract relief and adjust
pressure to 2200 psi (152 bar). Tighten nut.
1. Elevate the fully retracted boom to 70 degrees (full
elevation).
m. Lower rear end of machine.
2. At the positions indicated on Figure 2-15., Swing
Bearing Bolt Feeler Gauge Check, try and insert the
.0015" feeler gauge between the bolt head and hardened washer at the arrow indicated position.
2.17 SWING BEARING
3. Lower the boom to horizontal and fully extend the
boom.
Turntable Bearing Mounting Bolt Condition
Check
4. At the position indicated on Figure 2-15., Swing
Bearing Bolt Feeler Gauge Check, try and insert the
.0015" feeler gauge between the bolt head and hardened washer at the arrow indicated position.
NOTE: This check is designed to replace the existing bearing bolt torque checks on JLG Lifts in service. This
check must be performed after the first 50 hours of
machine operation and every 600 hours of machine
operation thereafter. If during this check any bolts
are found to be missing or loose, replace missing or
loose bolts with new bolts and torque to the value
specified in the torque chart, after lubricating the bolt
threads with loctite #271. After replacing and
retorquing bolt or bolts recheck all existing bolts for
looseness.
Check the frame to bearing. Attach bolts as follows:
1. Elevate the fully retracted boom to 70 degrees (full
elevation).
2. At the positions indicated on Figure 2-15., Swing
Bearing Bolt Feeler Gauge Check, try and insert the
.0015" feeler gauge between the bolt head and hardened washer at the arrow indicated position.
.0015" Feeler Gauge
Figure 2-15. Swing Bearing Bolt Feeler Gauge Check
3. Assure that the .0015" feeler gauge will not penetrate
under the bolt head to the bolt shank.
4. Swing the turntable 90 degrees, and check some
selected bolts at the new position.
5. Continue rotating the turntable at 90 degrees intervals until a sampling of bolts have been checked in
all quadrants.
2-32
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Wear Tolerance
1. From the underside of the machine, at rear center,
with the boom fully elevated and fully retracted (See
Figure 2-16.), using a magnetic base dial indicator,
measure and record the distance between the swing
bearing and the frame. (See Figure 2-17.)
2. At the same point, with the boom at horizontal
extended until red marking band on mid section is
exposed (See Figure 2-16.), using a magnetic base
dial indicator, measure and record the distance
between the swing bearing and frame. (See Figure
2-17.)
THE SWING BEARING IS ONE OF THE MOST CRITICAL POINTS
ON AN AERIAL LIFT. IT IS HERE THAT THE STRESSES OF LIFTING ARE CONCENTRATED, AT THE CENTER OF ROTATION.
BECAUSE OF THIS, PROPER MAINTENANCE OF THE SWING
BEARING BOLTS IS A MUST FOR SAFE OPERATION.
Replacement
1. Removal.
a. From ground control station, operate the boom
lift control and raise boom adequately to provide
access to frame opening or, if equipped, to the
rotary coupling.
3. If a difference greater than 1.625 mm (0.064 in.) is
determined, the swing bearing should be replaced.
4. If a difference less than 1.625 mm (0.064 in.) is
determined, and any of the following conditions
exist, the bearing should be removed, disassembled, and inspected for the following:
NEVER WORK BENEATH THE BOOM WITHOUT FIRST PROVIDING
ADEQUATE OVERHEAD SLING SUPPORT AND/OR BLOCKING.
b. Attach an adequate support sling to the boom
and draw all slack from sling. Block the boom if
feasible.
Metal particles in the grease.
Increased drive power required.
Noise.
Rough rotation.
c. From under side of machine frame, remove bolts
and lockwashers which attach rotary coupling
retaining yoke to coupling housing.
5. If bearing inspection shows no defects, reassemble
bearing and return to service.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DISCONNECTING LINES TO AVOID THE ENTRY OF
CONTAMINANTS INTO THE SYSTEM.
Figure 2-16. Swing Bearing Tolerance Boom Placement
3120819
– JLG Lift –
2-33
SECTION 2 - PROCEDURES
Figure 2-17. Swing Bearing Tolerance Measuring Point
d. Tag and disconnect the hydraulic lines from the
fittings on the top and sides of the rotary coupling. Use a suitable container to retain any
residual hydraulic fluid. Immediately cap lines
and ports.
e. Attach suitable overhead lifting equipment to the
base of the turntable weldment.
f. Use a suitable tool to scribe a line on the inner
race of the swing bearing and on the underside
of the turntable. This line will aid in aligning the
bearing upon installation. Remove the bolts,
nuts and washers which attach the turntable to
the bearing inner race. Discard the nuts and
bolts.
that the filler plug fitting is at 90 degrees from the
fore and aft centerline of the frame).
JLG INDUSTRIES RECOMMENDS THAT ALL REMOVED BEARING
NUTS AND BOLTS BE DISCARDED AND REPLACED WITH NEW
NUTS AND BOLTS. SINCE THE SWING BEARING IS THE ONLY
STRUCTURAL LINK BETWEEN THE FRAME AND TURNTABLE, IT
IS IMPERATIVE THAT SUCH REPLACEMENT HARDWARE MEETS
JLG SPECIFICATIONS. USE OF GENUINE JLG HARDWARE IS
HIGHLY RECOMMENDED.
b. Apply a light coating of Loctite #277 to the new
bearing bolts, and loosely install the bolts and
washers through the frame and outer race of
bearing.
g. Use the lifting equipment to carefully lift the complete turntable assembly from the bearing.
Ensure that no damage occurs to the turntable,
bearing or frame mounted components.
h. Carefully place the turntable on a suitably supported trestle.
i. Use a suitable tool to scribe a line on the outer
race of the swing bearing and the frame. This
line will aid in aligning the bearing upon installation. Remove the bolts and washers which
attach the outer race of the bearing to the frame.
Discard the bolts. Use suitable lifting equipment
to remove the bearing from the frame; move the
bearing to a clean suitably supported work area.
IF COMPRESSED AIR OR ELECTRICALLY-OPERATED IMPACT
WRENCH IS USED FOR TIGHTENING THE BEARING ATTACHMENT BOLTS, THE TORQUE SETTING ACCURACY OF THE TOOL
SHOULD BE CHECKED PRIOR TO USE.
2. Installation.
a. Use suitable lifting equipment to carefully lower
the swing bearing into position on the frame.
Ensure that the scribed line of the outer race of
the bearing aligns with the scribed mark on the
frame (if a new swing bearing is used, ensure
2-34
– JLG Lift –
c. Following the Torque Sequence diagram shown
in Figure 2-18., tighten the bolts to an initial
torque of 177 Nm (130 ft. lb.). Then following the
same sequence tighten the bolts to a final
torque of 230 Nm (170 ft. lb.) wet.
d. Remove the lifting equipment from the bearing.
e. Use suitable lifting equipment to carefully position the turntable assembly above the machine
frame.
f. Carefully lower the turntable onto the swing
bearing, ensuring that the turntable and bearing
align as noted in step a. above.
3120819
SECTION 2 - PROCEDURES
Figure 2-18. Swing Bearing Bolt Torquing Sequence
Swing Bearing Torque Values
IF COMPRESSED AIR OR ELECTRICALLY-OPERATED IMPACT
WRENCH IS USED FOR TIGHTENING THE BEARING ATTACHMENT BOLTS, THE TORQUE SETTING ACCURACY OF THE TOOL
SHOULD BE CHECKED PRIOR TO USE.
1. Outer Race - 230 Nm (170 ft. lb.) wet, 298 Nm (220
ft. lb.) dry.
g. Apply a light coating of Loctite #277 to the new
bearing bolts, and install the bolts, washers and
nuts through the turntable and inner race of the
bearing.
3. See Figure 2-18. for swing bearing bolt torquing
sequence.
h. Following the Torque Sequence diagram shown
in Figure 2-6, tighten the bolts to an initial torque
of 176 Nm (130 ft. lb.). Then following the same
sequence tighten the bolts to a final torque of
230 Nm (170 ft. lb.) wet.
RETORQUE INNER AND OUTER SWING BEARING BOLTS TO 220
FT. LB. (298 NM) AFTER FIRST 200 HOURS OF OPERATION AND
EVERY 500 HOURS THEREAFTER.
2. Inner Race - 230 Nm (170 ft. lb.) wet, 298 Nm (220 ft.
lb.) dry.
2.18 DRIVE TORQUE HUB
i. Remove the lifting equipment.
j. Install the rotary coupling retaining yoke; apply a
light coating of Loctite Sealant Number TL27741 to the attaching bolts and secure the yoke to
the rotary coupling with the bolts and lockwashers.
Disassembly
k. Connect the hydraulic lines to the rotary coupling as tagged prior to removal.
l. At ground control station, use boom lift control
to lower boom to stowed position.
m. Using all applicable safety precautions, activate
hydraulic system and functionally check swing
system for proper and safe operation.
3120819
– JLG Lift –
1. Position hub over suitable container and remove
drain plug (108) from unit. Allow oil to completely
drain.
2. Remove sixteen bolts (17), four socket head bolts
(18), and twenty lockwashers (20) from cover (301)
and lift cover from unit. Remove o-ring (5) from
counterbore of cover.
3. Disassemble cover (6) as follows:
a. Remove two bolts (303) securing disconnect
cap (304) to cover and remove disconnect
cover.
2-35
SECTION 2 - PROCEDURES
Figure 2-19. Drive Torque Hub
2-36
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
b. Remove two bolts (303) securing cover cap
(306) to cover and remove cap.
c. Remove disconnect rod (305) from cover cap
and remove o-rings (306 and 307) from cover
cap. discard o-rings.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
REMOVAL.
d. If necessary, remove pipe plug (309) from cover.
13. To remove cluster gear (206) from carrier, remove
retaining ring (208) from planet shaft (205) and drive
planet shaft out of carrier.
4. Remove two thrust washers (15) and thrust bearing
(16) from carrier counterbore. One thrust washer
may stick to cover. Inspect thrust washers and bearing for wear and replace if necessary.
5. Lift carrier assembly (3) from hub and spindle
assembly (1).
14. Cluster gear and bearings (203, 204) can now be
slid out of carrier and spacer (207) removed from
carrier bore. If bearing cups (203) require replacing
they can be driven out of cluster gear counterbores.
15. Repeat steps (12) and (13) for remaining cluster
gears.
6. Disassemble carrier as follows:
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
REMOVAL.
WHEN REBUILDING THE UNIT, O-RINGS AND RETAINING RINGS
SHOULD ALWAYS BE REPLACED.
a. Remove retaining (208) from planet shaft (205).
b. Remove spacer (207) from planet shaft, then,
using a suitable drift, drive planet shaft from carrier, shearing off roll pin. Tap remaining roll pin
from carrier using a suitable punch.
Cleaning and Inspection
c. Remove cluster (206) gear from carrier and
remove bearing cones (204) from cluster gear.
d. If necessary, press bearing cups (203) from cluster gear.
7. Lift ring gear (4) from housing (107). Remove o-ring
(5) from counterbore of ring gear and discard.
8. Remove input spacer (12), input (sun) gear (13),
input spacer (14), and input shaft (11) from spindle
(101).
9. Remove two thrust washers (15) and thrust bearing
(16) from end of spindle. One thrust washer may
stick in carrier counterbore. Inspect thrust washers
and thrust bearing for wear and replace if necessary.
2. Inspect geared or splined components in primary
and secondary planet carriers, input and output sun
gears, ring gear, coupling and input shaft for
chipped or broken teeth, and excessive or uneven
wear patterns. Replace components as necessary.
3. Inspect all thrust washers for scoring, pitting, erosion, discoloration or excessive wear. Replace thrust
washers as necessary.
4. Inspect all bearing cones and cups for scoring, pitting or excessive wear. If necessary, using a suitable
press, remove bearing cups from hub and replace
bearings as a set.
5. Inspect all needle rollers for scoring, pitting or
excessive wear. Replace all rollers as necessary.
10. Lift internal gear (2) out of hub.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
REMOVAL.
11. Remove ring keeper (21), retaining ring (106), and
thrust washer from end of spindle. Remove hub from
spindle.
12. Remove bearing cone (104) and seal (102) from
spindle (101). Seal will possibly hold bearing cone
into hub. If so, remove both from hub. If bearing
cups (103) require replacing they can be driven out
of hub counterbores. Discard seal and replace with
new seal.
3120819
1. Thoroughly clean all parts in an approved cleaning
solvent.
– JLG Lift –
6. Inspect planet gear pins for grooves, scoring or
excessive wear. Replace pins as necessary.
7. Inspect all threaded components for damage including stretching, thread deformation, or twisting.
Replace as necessary.
8. Inspect oil seal surfaces in hub and spindle for burrs
or sharp edges. Dress applicable surfaces or
replace components as necessary.
9. Inspect mating surfaces of hub, ring gear and cover
for burrs and sharp edges. Dress applicable surfaces or replace components as necessary.
2-37
SECTION 2 - PROCEDURES
Assembly
4. Place one thrust bearing (16) between two thrust
washers (15) and place them onto spindle pilot.
1. If necessary, assemble the hub/spindle assembly (1)
as follows:
a. With large open end of hub (107) up, press
bearing cup (103) into hub. If no press is available, bearing cup may be frozen and tapped into
place with a non-metallic faced hammer.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
INSTALLATION.
5. Install retaining ring (10) in groove of input shaft
(11).
b. Turn hub over, small diameter up. Install two
pipe plugs (110) into hub.
6. Place input shaft into spindle counterbore of hub/
spindle assembly. The action of the disengaged
spring should be checked at this time.
c. Press bearing cup (103) into small diameter end
of hub. If no press is available, bearing cup may
be frozen and tapped into place with a nonmetallic faced hammer.
7. Slide thrust spacer (12) onto input shaft.
d. Install bearing cone (104) into bearing cup.
e. Press seal (102) into hub counterbore with flat
metal side facing out. Use a flat object to ensure
that seal is pressed evenly and is flush with hub
face.
BEWARE OF SHARP EDGES OF COUNTERBORE WHILE SEATING
THIS O-RING.
f. Lower hub onto spindle (101) with large open
end up.
8. Place o-ring (5) into counterbore of hub/spindle
assembly. Use grease or petroleum jelly to hold oring in place.
g. Place bearing cone (104) over end of spindle
and into bearing cup.
9. Assemble carrier assembly (3) as follows:
h. Place bearing shim (105) over end of spindle
and against bearing cone.
a. Press bearing cups (203) into both ends of cluster gear (206) with large inside diameter facing
out. Use an arbor type press with a 5.110 diameter adapter tool.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
INSTALLATION.
b. Place planet shaft (205) on a flat surface with
large diameter down. Place one bearing cone
(204) over shaft and against shoulder. This
should be a slip fit.
i. Secure retaining ring (106) completely into spindle groove and against bearing shim. Ensure
retaining ring is entirely in groove.
j. Install retaining ring keeper ring (21) in location
around retaining ring and on bearing spacer.
k. With large open end of hub/spindle assembly
facing up, place one spacer washer (7) into spindle counterbore.
l. Place spring (8) into spindle counterbore.
m. Set second spacer washer (7) on top of spring.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
INSTALLATION.
n. Compress spacer washer and spring into spindle counterbore and install retaining ring (9) into
spindle groove.
2. Position hub/spindle assembly (1) with large open
end up.
3. Lower internal gear (2) onto spindle.
2-38
c. Place cluster gear over planet shaft and onto
bearing cone, with large gear on top.
d. Place another bearing cone (204) over planet
shaft and into cluster gear. This is a slip fit.
e. Slide largest spacer (207) onto planet shaft.
f. Bearings in cluster gear must be seated by
applying 11-23 kg (25-50 lb.) against them and
rotating cluster gear at the same time. This can
be done by sliding a second spacer (207) over
planet shaft and pushing downward while rotating the gear.
g. See if retaining ring (208) will fit onto planet shaft
groove. If not, try smaller spacer (207) until
retaining ring fits. This will set bearings at 0.000.15 mm (0.000-0.006 inch).
h. Place carrier on edge of a table with one set of
holes hanging over the edge. Side with roll pin
hole should be down.
i. Place bearing cones (203) into cluster gear.
j. Place cluster gear into carrier with large gear up.
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
k. Slide planet shaft through carrier and cluster
gear from bottom side. Slot in planet shaft must
line up with roll pin hole in edge of carrier.
positioned in line with one of four counterbored
holes in face of hub. These holes have been counterbored to accept four shoulder bolts upon installation of cover.
l. While holding planet shaft in position, slide correct spacer onto planet shaft.
EYE PROTECTION SHOULD BE WORN DURING RETAINING RING
INSTALLATION.
m. Place carrier on table with something under
planet shaft to hold it in correct position and
install retaining ring (208).
14. Thrust spacer (14), input gear (13), and input spacer
(12) are installed onto input shaft (11). Counterbore
in input gear should be facing thrust spacer.
15. Place one thrust bearing (16) between two thrust
washers (15) and place into carrier counterbore.
16. Assemble cover assembly as follows:
a. Screw pipe plug (309) into cover (301).
b. Install o-ring (307) over cover cap.
EYE PROTECTION SHOULD BE WORN DURING THIS OPERATION.
c. Install o-ring (306) into bore of cover cap (302).
Disconnect rod (305) may be used to push oring down to groove in cover cap bore.
n. Drive roll pin (202) into carrier. Use a punch to
drive roll pin completely into planet shaft.
o. Repeat steps (a) through (n) for remaining two
cluster gears.
d. Push disconnect rod into bore of cover cap.
10. Time carrier gears as follows:
e. Locate large clearance hole in cover cap over
pipe plug in cover and install cover cap in cover.
Use two bolts (303) torqued to 95-108 Nm (7080 ft. lb.).
a. Place carrier assembly on a flat surface, positioning two top gears at ten o’clock and two
o’clock, and one bottom gear at six o’clock as
shown below.
f. Install disconnect cap (304) to cover cap with
two remaining bolts (303) torqued to 95-108 Nm
(70-80 ft. lb.).
BEWARE OF SHARP EDGES OF COUNTERBORE WHILE SEATING
THIS O-RING.
g. Place o-ring (5) into cover counterbore. Use
petroleum jelly to hold o-ring into place.
b. Find marked (punch mark) teeth on large gears.
Rotate gears until punch mark is located in a
straight up, 12 o’clock, position. Punch marks at
ten o’clock and two o’clock will be located just
under edge of carrier and not readily visible.
11. Taking care to ensure that timing is maintained,
install ring gear (4) in mesh with large diameter cluster gear. Side of ring gear with long shoulder is
installed down.
12. While holding ring gear in mesh with carrier assembly, lower into internal gear (2). Small diameter cluster gear will mesh with internal gear. Slight rotation
of ring gear may be necessary.
13. Locate the one hole on underside of ring gear that
has an “X” stamped beside it. This hole should be
3120819
17. Place cover assembly (6) onto ring gear (4). Rotate
cover assembly until pipe plug (309) is located 90
degrees and 180 degrees from pipe plugs (110) in
opposite end of hub.
18. Secure cover assembly and ring gear to hub with
four shoulder bolts (18) and lockwashers (20).
Shoulder bolts fit into four counterbored holes in
hub. It may be necessary to start bolts into hub by
tapping lightly on bolts with a hammer.
19. Install sixteen Grade 8 bolts (17) and lockwashers
(20) in remaining holes.
20. Tighten bolts and shoulder bolts evenly and torque
to 136-149 Nm (100-110 ft. lb.).
21. Install coupling (19) into spindle onto input shaft.
– JLG Lift –
2-39
SECTION 2 - PROCEDURES
dle rollers (13) on each shaft are not damaged
or lost.
2.19 SWING TORQUE HUB
c. Lift cluster gears (11) from carrier (10) and
remove thrust washers (12), needle rollers (13)
and roller spacer (14).
Disassembly
1. Remove oil plugs (25 and 26) and drain oil from unit
into a suitable container. Replace drain plugs.
NOTE: The screws, hub pinion gear, and retaining plate referenced in steps (2) and (3) are not shown in Figure
2-9, but are attached to the hub output shaft (item
30).
d. Drive roll pins (16) from shafts (15) and discard
pins.
17. If necessary, disassemble hub and shaft assembly
(24) as follows:
a. Using suitable snap ring pliers, remove retaining
ring (20) from groove in output shaft (30).
2. Remove the two screws which attach the hub pinion
gear retaining plate and remove plate.
b. Remove spacer shim (21) from output shaft.
3. Carefully remove pinion gear from splined hub output shaft.
c. Place hub in a suitable hand-operated hydraulic
press with external portion of shaft (30) down
and with suitable block supporting hub (24).
d. Using suitable protection between inner end of
shaft (30) and press cylinder drift, operate press
and carefully press shaft from inner bearing
assembly (22 and 23).
4. Using suitable protection, clamp drive hub assembly
in a vise or suitable holding fixture.
5. Remove four shoulder bolts (3) and lockwashers (4)
from counterbored holes in cover of drive hub
assembly.
e. Remove seal (29) from shaft and discard seal.
f. Remove bearing cone (22) from cup (23).
6. Remove remaining eight bolts (2) which attach cover
(1) to ring gear (7).
7. Carefully remove cover assembly (1) from input gear
(18) together with outer thrust washers (8) and thrust
bearing (9). Remove and discard outer o-ring (6).
g. Using press, remove bearing cups (23 and 27)
from hub (24) and cone (28) from shaft (30).
Cleaning and Inspection
1. Clean all parts thoroughly in an approved cleaning
solvent.
8. Remove thrust washer (17) from small diameter of
input gear (18).
9. Carefully withdraw input gear (18) from cluster gear
(11) and output shaft (30).
2. Inspect bearing components (22, 23, 27, 28) for
damage, pitting, corrosion or excessive wear.
Replace bearings as a complete set if necessary.
10. Rotate ring gear (7) and check that each of the three
cluster gears (11) incorporates a punched timing
mark.
3. Inspect all thrust washers for scoring or excessive
wear.
4. Inspect all geared or splined components for
chipped or broken teeth and for excessive or
uneven wear patterns.
11. Carefully withdraw ring gear (7) from assembly.
12. Carefully withdraw carrier assembly (10) from internal gear (19).
5. Inspect o-ring grooves in hub (24) and cover (1) for
burrs or sharp edges. Dress applicable surfaces as
necessary.
13. Remove and discard inner o-ring (5).
14. Remove inner thrust washers (8) and thrust bearing
(9) from counterbore in carrier assembly (10).
6. Inspect all thrust washer and bearing surfaces for
damage. Repair or replace as necessary.
15. Carefully withdraw internal gear (19) from output
shaft (30).
7. Inspect all threaded components for damage including stretching, thread deformation or twisting.
Replace as necessary.
16. If necessary, disassemble planet carrier assembly
(10) as follows:
a. Remove three pins (16) by gently tapping a suitable punch against the roll pin until the pin is
driven into planet shaft (15).
8. Inspect planet shafts (15) for scoring or other damage. Replace as necessary.
Assembly
b. Using a suitable drift, carefully and gently tap
shafts (15) from carrier (10), ensuring that nee-
2-40
– JLG Lift –
1. If necessary, assemble hub and shaft assembly.
3120819
SECTION 2 - PROCEDURES
Figure 2-20. Swing Torque Hub
3120819
– JLG Lift –
2-41
SECTION 2 - PROCEDURES
a. Using a suitable hydraulic press, install bearing
cups (23 and 27) into hub (24).
j. Position new roll pin (16) in hole in carrier (10)
and drive pin into hole until end of pin is flush
with carrier surface.
b. Using the hydraulic press, install bearing cone
(28) onto output shaft (30).
k. Repeat steps (a) through (j) for remaining two
cluster gears.
c. Correctly position shaft (30) into hub (24) with
cone (28) in cup (27).
3. Position internal gear (19) on inner end of output
shaft (30).
d. Using a suitable shaft support in the hydraulic
press, install bearing cone (22) on shaft (30)
until cone abuts bearing cup (23).
4. Time carrier cluster gears as follows:
a. Place carrier assembly on a flat surface, positioning two top gears at ten o’clock and two
o’clock, and one bottom gear at six o’clock as
shown in Figure 2-8.
e. Position spacer shim (21) on shaft (30) between
retainer ring groove and bearing cone (22).
f. Using suitable snap ring pliers, install retaining
ring (20) on shaft (30).
b. Find marked (punch mark) teeth on large gears.
Rotate gears until punch mark is located in a
straight up, 12 o’clock, position. Punch marks at
ten o’clock and two o’clock will be located just
under edge of carrier and not readily visible.
g. Using the hydraulic press, install a new seal (29)
over shaft and into hub (24). Ensure that seal is
installed squarely.
h. Check that output shaft (30) rotates freely in the
hub. The oil seal will create a small amount of
drag. By tapping the outside of the shaft with a
soft headed mallet, any excessive tightness will
be reduced.
5. Place ring gear (7) over cluster gears (11), with
raised shoulder of ring gear facing down.
6. While holding ring gear (7) in position, invert carrier
assembly (10) so that ring gear and larger diameter
of cluster gears (11) are facing down.
2. If necessary, assemble planet carrier assembly (10)
as follows:
7. Apply a light coating of petroleum jelly or multi-purpose grease to inner thrust washer (8) and thrust
bearing (9).
a. Apply a light coating of petroleum jelly or multipurpose grease to flanged surface of thrust
washers (12).
8. Position thrust washer (8), thrust bearing (9), and
thrust washer (8) into applicable groove of carrier
assembly (10).
b. Position thrust washers (12) in carrier (10) with
tang in appropriate carrier cutaway portion.
Ensure that washers are flat against surface on
both sides of carrier.
c. Apply a liberal coating of petroleum or multi-purpose grease to inner diameter of cluster gear
(11).
10. Position o-ring (6) in groove in hub (24).
d. Position spacer (14) at the approximate midpoint
of the gear diameter.
11. While holding ring gear (7) and carrier assembly
(10), insert smaller diameter of cluster gears (11)
into internal gear (19).
e. On each side of spacer (14), position needle rollers (13) in inner diameter of gear.
12. Rotate ring gear (7) until hole marked “X” is located
over hub shaft assembly (24).
f. Position assembled cluster gear (11) into carrier
(10) between the two thrust washers (12).
Ensure that larger gear is on the roll pin side of
carrier.
13. Insert input gear (18) into carrier assembly (10) so
that input gear and larger diameter of cluster gears
(11) are in mesh. Check that carrier assembly (10)
rotates freely.
g. Position planet shaft (15) into carrier hole, with
shaft roll pin hole on same side as carrier roll pin
hole.
14. Position thrust washer (17) on shaft of input gear
(18).
h. Continue inserting shaft through thrust washers
(12) and cluster gear (11). Ensure that needle
rollers (13) are not displaced.
i. Align roll pin holes in both shaft (15) and carrier
(10) with chamfered portion of shaft hole uppermost.
2-42
9. Apply a light coating of petroleum jelly or multi-purpose grease to new inner o-ring (6).
15. Apply a light coating of petroleum jelly or multi-purpose grease to new outer o-ring (6).
16. Position o-ring (6) into groove of cover (1).
17. Apply a light coating of petroleum jelly or multi-purpose grease to outer thrust washers (8) and thrust
bearing (9).
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
18. Position outer thrust washer (8), thrust bearing (9)
and thrust washer (8) in cover (1).
19. Position cover (1) on ring gear (7) with oil check
plug (5) in cover located at 90° from oil fill plugs (25
and 26) in hub (24).
20. Install four shoulder bolts (3) and lockwashers (4)
into appropriate counterbored holes in hub (24).
21. Install eight bolts (2) which attach cover (1) to ring
gear (7) and hub (24) and tighten to a torque of 3137 Nm (23-27 ft. lb.).
8. Remove retaining ring (18) from housing (21).
9. Remove shaft by pressing or using a soft mallet on
male end of shaft (10).
NOTE: Earlier models did not use retaining ring (22).
10. Remove retaining ring (22) and bearing (19) from
shaft (10).
11. Press Rotary oil seal (23) from housing (21).
Cleaning and Inspection
22. Carefully install hub pinion gear on splined output
shaft. If necessary, gently tap into position with a soft
headed mallet.
1. Clean all parts thoroughly.
2. Closely inspect all parts for excessive wear, cracks,
and chips. Replace parts as necessary.
23. Apply No. 2 Lift Grade Loctite to pinion gear retaining plate screws.
3. Discard seals and o-rings.
24. Position gear retaining plate and install attaching
screws.
25. Remove oil fill plug (25 or 26) and fill hub assembly
with approximately one quart of approved extreme
pressure gear lubricant. Install fill plug.
4. Closely inspect bearings and bearing contact surfaces. Replace as necessary.
NOTE: Bearings may be reused if, after thorough inspection,
they are found to be in good condition.
Assembly
2.20 SWING BRAKE
1. Separate end cover (2) from housing (21) by removing capscrews (1).
NOTE: Lubricate all seals and o-rings with clean hydraulic
oil prior to assembly.
1. Clean all parts thoroughly before assembly.
END COVER IS UNDER SPRING TENSION OF APPROXIMATELY
2,000 LB. (907 KG). THE FOUR BOLTS SHOULD BE LOOSENED
EVENLY TO RELIEVE THIS FORCE. IF A HYDRAULIC PRESS IS
AVAILABLE (1,360 KG [3,000 LB.] MINIMUM), THE COVER CAN BE
HELD IN POSITION WHILE REMOVING THE CAPSCREWS AND
LOCKWASHERS.
2. Press new rotary oil seal (23) into housing (21). Note
direction of the seal.
NOTE: Earlier models did not use retaining ring (22).
3. Install new bearing (19) and retaining ring (22) on
shaft (10).
2. Remove case seal (4) from the housing (21), then
remove bleeder screw (3) from the end cover (2).
4. Insert shaft assembly and retaining ring (18) in housing (21).
3. Remove piston (7) from end cover (2).
4. Remove o-ring (5), back-up ring (6), o-ring (8) and
back-up ring (9) from piston (7).
NOTE: Be sure to use the same number of springs and
spring pattern as recorded during disassembly.
Spring retainer (17) was not used in earlier models.
5. Remove separators (13) from housing (21).
5. Insert dowel pins (20), spring retainer (17) and
springs (15 & 16) in housing (21).
6. Remove stack assembly, consisting of discs (11),
return plate (14) and friction discs (12) from housing
(21).
6. Position new large diameter return plate (14) in
housing with tabs guided by dowel pins (20) until
disc rests on springs (15 & 16).
NOTE: Not all models use the same number of springs or
spring pattern. Record this information for assembly
purposes. Spring retainer (17) was not used in earlier models.
7. Remove dowel pins (20), springs (15 & 16) and
spring retainer (17) from housing (21).
3120819
DISCS (11, 14) AND FRICTION DISCS (12) SHOULD REMAIN DRY
DURING INSTALLATION. NO OIL RESIDUE SHOULD BE ALLOWED
TO CONTAMINATE DISC SURFACES.
– JLG Lift –
2-43
SECTION 2 - PROCEDURES
Figure 2-21. Swing Brake
2-44
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
7. Place a new friction disc (12) on shaft (10) until it
contacts return plate (14).
6. Remove stack assembly, consisting of discs (23),
return plate (8) and friction discs (22) from housing.
8. Add additional new discs (11) and new friction discs
(12) as required to complete assembly.
7. Remove dowel pins (17), springs (5 and 6) and
spring retainer (16) from housing.
9. Insert separators (13) in holes of return plate.
10. Install new o-ring (5), new backup ring (6), new oring (8) and new back-up ring (9) on piston (7). Note
order of o-rings and back-up rings. Insert piston (7)
into end cover (2) being careful not to shear o-rings
or back-up rings.
11. Install new case seal (4) in housing (21) then install
bleeder screw (3) in end cover (2).
12. Position end cover (2) on housing (21) aligning
dowel pins (20) with holes in end cover.
NOTE: If available, a hydraulic press will simplify installation
of end cover on housing. Clamp cover in position
while tightening capscrews.
NOTE: Not all models use the same number of springs or
spring pattern. Record this information for assembly
purposes.
8. Remove retaining ring (3) from housing.
9. Remove shaft (4) by pressing or using a soft mallet
on male end of shaft.
10. Remove retaining ring (15) and bearing (2) from
shaft.
11. Press rotary oil seal (1) from housing, then remove
gasket (27) and o-ring (26) from housing.
Inspection
1. Clean all parts thoroughly.
13. Press on inner ring of bearing (37) until it shoulders
on shaft (45) to eliminate binding on bearings. Be
certain to restrain opposite end of shaft to avoid
excessive thrust loading on bearing (54).
IF HYDROSTATIC BENCH TESTING IS PERFORMED ON THE
BRAKE ASSEMBLY, RELEASE PRESSURE SHOULD NOT EXCEED
138 BAR (2000 PSI) UNLESS TWO ADDITIONAL BOLTS ARE USED
FOR SUPPLEMENTAL CLAMPING.
2. Closely inspect all parts for excessive wear, cracks
and chips. Replace parts as necessary.
3. Discard seals and o-rings.
4. Closely inspect bearings and bearing contact surfaces. Replace as necessary.
NOTE: Bearings may be re-used if, after thorough inspection, they are found to be in good condition.
Assembly
2.21 DRIVE BRAKE
NOTE: Lubricate all seals and o-rings with clean hydraulic
oil prior to assembly.
Disassembly
1. Remove end cover (13) from housing (7) by removing washer head bolts (12).
1. Install new gasket (27) and o-ring (26) in housing
(7).
2. Press new rotary oil seal (1) into housing. Note
direction of seal.
END COVER IS UNDER SPRING TENSION OF APPROXIMATELY
2,000 LB. (907 KG). THE FOUR WASHER HEAD BOLTS SHOULD
BE LOOSENED EVENLY TO RELIEVE THIS FORCE. IF A HYDRAULIC PRESS IS AVAILABLE (1,360 KG [3,000 LB.] MIN.), THE
COVER CAN BE HELD IN POSITION WHILE REMOVING THE
WASHER HEAD CAP SCREWS.
3. Install new bearing (2) and retaining ring (15) on
shaft (4).
4. Insert shaft assembly and retaining ring (3) in housing.
2. Remove case seal (11) from housing, then remove
bleeder screw (14), o-ring (28) and gasket (29) from
end cover.
3. Remove piston (24) from end cover.
4. Remove o-ring (19), back-up ring (18), o-ring (21)
and back-up ring (20) from piston.
5. Remove separator assemblies (9, 10) from housing.
3120819
– JLG Lift –
2-45
SECTION 2 - PROCEDURES
Figure 2-22. Drive Brake, Mico
2-46
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
5. Insert dowel pins (17), spring retainer (16) and
springs (5 and 6) in housing. Insert the springs as
shown in Figure 2-23., Spring Loading.
12. Position end cover on housing, aligning dowel pins
with holes in end cover.
13. Install washer head bolts (12) and tighten evenly to
draw end cover to housing. Torque washer head
bolts to 75 Nm (55 ft. lb.).
NOTE: If available, a hydraulic press will simplify installation
of end cover on housing. Clamp cover in position
while tightening the washer head bolts.
14. If hydrostatic bench testing is performed on the
brake assembly, release pressure should not
exceed 138 bar (2,000 psi) unless two additional
bolts are used for supplemental clamping.
2.22 FREE WHEELING OPTION
To Disengage Drive Motors and Brakes (Free
Wheel) for Towing, etc
1. Chock wheels securely if not on flat level surface.
2. Disconnect both drive hubs by inverting disconnect
caps in center of hubs.
Figure 2-23. Spring Loading
3. If equipped, move steer/tow selector valve to float
(tow) position by pulling valve knob out.
NOTE: Be sure to use the same number of springs and
spring pattern as recorded during disassembly.
6. Position new large diameter return plate (8) in housing with tabs guided by dowel pins until disc rests
on springs.
To Engage Drive Motors and Brakes (Normal
Operation)
NOTE: Discs (8 and 23) and friction discs (22) should
remain dry during installation. No oil residue should
be allowed to contaminate disc surfaces.
7. Place a new friction disc (22) on shaft until it contacts return plate.
1. If equipped, move steer/tow selector valve to steer
position by pushing valve knob in.
2. Connect both drive hubs by inverting disconnect
cap in center of hub.
3. Remove chocks from wheels as required.
8. Add additional new discs (23) and new friction discs
as required to complete assembly.
9. Insert separator assemblies (9 and 10) in holes of
return plate.
10. Install new o-ring (19), new back-up ring (18), new oring (21) and new back-up ring (20) on piston (24).
Note order of o-rings and back-up rings. Insert piston into end cover (13), being careful not to shear orings or back-up rings.
11. Install new case seal (11) in housing, then install
bleeder screw (14), gasket (27) and o-ring (26) in
end cover.
3120819
– JLG Lift –
2-47
SECTION 2 - PROCEDURES
2.23 PQ CONTROLLERS
Table 2-6. Platform Controller Settings (S/N 38697 to
Present)
NOTE: The following procedures are to be used as a beginning basis for controller adjustment. After completing
the procedure, final adjustments are to be made
based on the machines function speed.
Function
Table 2-4. Function Speeds
Function Speed
In Seconds
(Prior to S/N
38697)
Function
In Seconds
(S/N 38697
to Present)
Settings in mA
Lo
Mid
Hi
Ramp
Turns
Lift
200
400
1100
6
Swing
200
400
1100
6
Drive
40
70
180
10
Flow Control
170
N/A
1000
N/A
TRIM Adjustment (Prior to S/N 38697)
1. Perform the following checks with ignition power to
the platform, with the engine NOT running.
Telescope
Extend
132-170
80-100
Retract
140-175
75-100
1. Install ammeter capable of measuring from zero to 2
amps in series with either valve coil B or D.
Up
125-160
85-100
Down
108-132
75-100
2. Position IGNITION/EMERGENCY STOP switch to
ON, but do not start engine.
Up
15-25
15-25
3. Using a screwdriver, adjust the ramp trimpot counterclockwise 25 turns or until the trimpot clicks.
Down
15-25
15-25
4. Depress footswitch.
160-200
160-200
Left
20-30
20-30
Right
20-30
20-30
257-330
165-200
248-307
150-200
505-637
315-400
46-56 @ 200ft.
46-56 @ 200ft.
Lift
Extend-A-Reach
Swing Speed
Full 360
5. Operate controller until trailing edge of slide lock is
even with housing lock notch. Hold control handle in
that position.
Platform Rotation
6. Check the mA reading in the opposite direction.
7. Operate the controller until the trailing edge of the
slide lock is even with the housing lock notch. Hold
the control handle in that position. Check the mA
reading.
Ground to 120’
From 120’ to Ground
8. Verify step 7 and step 8 mA readings are within 0.50
mA of each other. If the readings are within tolerance, proceed to step 12.
Ground to 120’ to Ground
Drive Speed
9. If the readings in step 9 were not within tolerance,
Loosen the setscrew located in the gear on the
potentiometer shaft of the controller. Using a screwdriver, adjust the potentiometer very slightly in either
direction. Tighten the setscrew on the gear and
recheck for the proper mA readings. Repeat this
step until the proper adjustment is obtained.
Table 2-5. Platform Controller Settings (Prior to S/N
38697)
Function
Settings in mA
Lo
Hi
Lift
300
500
Swing
300
500
10. Place the creep toggle switch in the off position.
11. Using correct size common blade screwdriver,
adjust LO trimpot until ammeter indicates the proper
value as shown in Table 2-4, Function Speeds.
Clockwise rotation of trimpot adjust screw increases
ammeter; counterclockwise rotation decreases
ammeter reading.
12. Operate controller in the same direction as in step 6
to the full extent of its travel and hold handle in that
position.
2-48
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
13. Adjust HI trimpot until ammeter the value shown in
Table 2-4, Function Speeds.
TRIM Adjustment (S/N 38697 to Present)
NOTE: For the following procedure, disconnect the controllers at the following locations:
14. Repeat step 13.
15. Place the creep toggle switch in the creep on position. Adjust the mid trimpot to the value shown in
Table 2-4, Function Speeds.
Flow Control Card: Terminal Strip 23 Red/Orn
wire (turn knob to obtain setting)
Lift Controller: Terminal Strip 27 Blk/Yel Wire
Swing Controller: Terminal Strip 24 Blu/Orn
wire
16. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to HI trimpot adjustment, and
must be readjusted back to the value shown in Table
2-4, Function Speeds.
1. Perform the following checks with ignition power to
the platform, with the engine NOT running and the
controllers disconnected as outlined in the note
above.
17. Move handle to the position given in step 13 and
check ammeter reading. This reading too will have
changed due to LO trimpot readjustment, and must
be adjusted back to the value shown in Table 2-4,
Function Speeds.
2. Install ammeter capable of measuring from zero to 2
amps in series.
3. Position IGNITION/EMERGENCY STOP switch to
ON, but do not start engine.
18. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to MID trimpot adjustment, and
must be readjusted back to the value shown in Table
2-4, Function Speeds.
4. Using a screwdriver, adjust the ramp trimpot counterclockwise 25 turns or until the trimpot clicks.
5. Depress footswitch.
6. Operate controller until 1/2 of slide lock is out of the
housing lock notch. Hold control handle in that position.
19. Repeat steps 17 and 18 until LO and HI readings as
shown in Table 2-4, Function Speeds can be
achieved without further trimpot adjustments.
7. Check the mA reading in the opposite direction.
20. Adjust the Ramp trimpot 6 turns clockwise.
8. Operate the controller until 1/2 of the slide lock is out
of the housing lock notch. Hold the control handle in
that position. Check the mA reading.
21. Release footswitch.
22. Connect ORANGE/RED (dump) wire to terminal strip
number 3 in platform console.
23. Using all applicable safety precautions, start
machine and allow hydraulic oil to reach a temperature of 100° F - 140° F (38° - 60° C).
24. Depress footswitch and operate controller until trailing edge of slide lock is even with housing lock
notch. Hold control handle in that position.
25. Adjust LO trimpot until applicable function just starts
to work. Immediately stop adjustment.
26. Release footswitch and stop machine.
27. Seal each trimpot with a drop of enamel paint to prevent maladjustment due to vibration.
9. Verify step 7 and step 8 mA readings are within 0.50
mA of each other. If the readings are within tolerance, proceed to step 11.
10. If the readings in step 9 were not within tolerance,
Loosen the setscrew located in the gear on the
potentiometer shaft of the controller. Using a screwdriver, adjust the potentiometer very slightly in either
direction. Tighten the setscrew on the gear and
recheck for the proper mA readings. Repeat this
step until the proper adjustment is obtained.
11. Place the creep toggle switch in the off position.
12. Position the Controller as outlined in step 6. Using
correct size common blade screwdriver, adjust LO
trimpot until ammeter indicates the proper value as
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present). Clockwise rotation of trimpot
adjust screw increases ammeter; counterclockwise
rotation decreases ammeter reading.
13. Operate controller in the same direction as in step 6
to the full extent of its travel and hold handle in that
position.
3120819
– JLG Lift –
2-49
SECTION 2 - PROCEDURES
14. Adjust HI trimpot until ammeter indicates the value
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present).
15. Repeat step 13.
16. Place the creep toggle switch in the creep on position. Adjust the mid trimpot to the value shown in
Table 2-6, Platform Controller Settings (S/N 38697 to
Present) for mid.
17. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to HI trimpot adjustment, and
must be readjusted back to the value shown in Table
2-6, Platform Controller Settings (S/N 38697 to
Present).
RAMP Adjustment
Controllers equipped with the RAMP feature actually compensate for abrupt control handle operation by slowing
the response time of the output signal regardless of the
speed with which the handle is moved.
IT SHOULD BE REMEMBERED THAT THE RAMP FEATURE OPERATES IN BOTH DIRECTIONS OF THE PARTICULAR PROPORTIONA L FUNC TION. THEREFORE A DJU STI NG TH E R AMP
POTENTIOMETER TO PROVIDE A DELAY IN STARTING A FUNCTION WILL PROVIDE A CORRESPONDING DELAY IN STOPPING
THAT FUNCTION.
1. Drive Controller.
a. Using all applicable safety precautions, start
machine and ensure that adequate space is
available to maneuver machine.
18. Move handle to the position given in step 13 and
check ammeter reading. This reading too will have
changed due to LO trimpot readjustment, and must
be adjusted back to the value shown in Table 2-6,
Platform Controller Settings (S/N 38697 to Present).
19. Move controller handle back to the position given in
step 6 and check ammeter reading. This reading will
have changed due to MID trimpot adjustment, and
must be readjusted back to the value shown in Table
2-6, Platform Controller Settings (S/N 38697 to
Present).
b. Position ENGINE SPEED switch to HIGH and
DRIVE SPEED switch to HIGH.
NOTE: Clockwise rotation of the ramp potentiometer adjust
screw increases ramp (delay) time; counterclockwise
rotation decreases ramp (delay) time.
20. Repeat steps 17 and 18 until LO and HI readings as
shown in Table 2-6, Platform Controller Settings (S/N
38697 to Present) can be achieved without further
trimpot adjustments.
21. Adjust the Ramp trimpot clockwise according to
Table 2-6, Platform Controller Settings (S/N 38697 to
Present).
22. Release footswitch.
d. Operate machine drive function in the opposite
direction and check that stopping distance of
20-30 cm (8-12 in.) is maintained.
e. Release footswitch and stop machine.
f. Seal ramp pot adjustment screw with a drop of
enamel paint to prevent maladjustment due to
vibration.
g. Install controller and secure machine.
23. Using all applicable safety precautions, start
machine and allow hydraulic oil to reach a temperature of 100° F - 140° F (38° - 60° C).
24. Depress footswitch and operate controller until 1/2
of slide lock is out of the housing lock notch. Hold
control handle in that position.
25. Adjust LO trimpot until applicable function just starts
to work. Immediately stop adjustment.
26. Release footswitch and stop machine.
27. Seal each trimpot with a drop of enamel paint to prevent maladjustment due to vibration.
2-50
c. Operate machine drive function and adjust ramp
pot so that machine will stop within 20-30 cm (812 in.) when the control handle is released from
the full extent of its travel.
– JLG Lift –
2. Swing Controller.
a. Using all applicable safety precautions, start
machine and ensure that adequate space is
available to maneuver machine.
b. Fully extend boom at horizontal.
c. Position ENGINE SPEED switch to LOW.
d. Operate SWING controller at full speed to the left
and then quickly move controller to the full
speed RIGHT position. The platform should
slow, stop and then swing right in one smooth
and continuous operation.
e. If control valve initiates swing right motion before
platform momentum is stopped, the ramp potentiometer adjust screw should be rotated clockw is e to inc r e as e ra mp t im e and t he te s t
repeated.
3120819
SECTION 2 - PROCEDURES
Figure 2-24. Boom Marking Tape Installation
f. If after operating SWING function as described
in step (d), the platform stops moving to the left
and the spring action of the boom tends to initiate the swing right motion before the control
valve starts to operate, the ramp pot adjust
screw should be rotated counterclockwise to
decrease ramp time.
g. Repeat the test in both swing directions.
2.24 BOOM MARKING TAPE INSTALLATION
Boom marking tape installation is shown in Figure 2-24.
2.25 BOOM LENGTH/ANGLE SENSOR
ADJUSTING PROCEDURE
NOTE: The boom length and angle sensor adjustments
need to be made before the display lights are
adjusted.
h. Release footswitch and stop machine.
i. Seal ramp pot adjustment screw with a drop of
enamel paint to prevent maladjustment due to
vibration.
The boom length and angle sensor is factory set and
does not normally require adjusting unless it is
removed from the base boom for maintenance.
j. Install controller and secure machine.
3120819
– JLG Lift –
2-51
SECTION 2 - PROCEDURES
Length Indicator Adjustment
Boom Angle Sensor Adjustment
1. Level the frame before beginning any adjustments.
1. With the platform level, the boom fully retracted and
at 45 (+/- 1) degrees elevation, measure the DC
voltage at TP5 on the Load Radius Circuit Card.
2. Make all adjustments with the engine running unless
otherwise noted.
2. Loosen the three screws securing the sensor to the
box and rotate the sensor until 7.1 (+/- 0.1) Volts DC
is measured at TP5. Tighten the screws on the sensor.
3. Fully retract the boom.
4. On the Load Radius Circuit Card, measure TP10 and
insure that 10 (+0.1/-0) Volts DC is present.
5. On the Load Radius Circuit Card, adjust P1 to 1.223
Volts DC while measuring TP1.
6. Make the following adjustment with the power off.
a. On the Load Radius Circuit Card, disconnect
connector J2 (the 6 pin connector on the printed
circuit board). Measure between Pin (6) of the
socket connector and ground (TB1-1), adjust
potentiometer P5 to a value of 1915 (+/- 5)
Ohms.
3. Return the boom to horizontal.
Radius Adjustment and Display Lights
Setting Procedure
b. Adjust the 5K Ohm potentiometer in the boom
cable reel by loosening the three screws holding
it in place.
NOTE: When checking the resistance on the 6 pin connector as outlined in step (c), be sure to use connector
pins (6) and (3) corresponding to pins (6) and (3) on
plug 2 on the circuit card.
c. Rotate the 5K Ohm potentiometer until you measure 100 Ohms between Pin (3) and Pin (6) on
the 6 pin plug connector which mates with J2.
d. Tighten the three (3) screws on the 5K Ohm
potentiometer in the boom cable reel.
1. On the Load Radius Circuit Card, measure TP11 and
adjust potentiometer P6 for a reading of 0.525 Volts
DC.
2. On the Load Radius Circuit Card, measure TP8 and
adjust potentiometer P2 for a reading of 2.050 Volts
DC.
3. On the Load Radius Circuit Card, measure TP9 and
adjust potentiometer P3 for a reading of 5.0 Volts
DC.
4. Telescope the boom until the leading edge of the red
marking tape is exposed from the mid boom. Adjust
potentiometer P2 until the red light just turns on and
the blue light turns off.
5. Measure TP2 and adjust potentiometer P4 until TP7
measures 0.05 Volts DC more than TP2. This determines the length of the boom (critical length) where
the lift down speed limiter is turned on.
7. Turn the power on and measure TP2. It should be
1.287 Volts DC. Re-adjust the 5K Ohm potentiometer
if necessary.
2-52
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Operational Check
1. Raise the boom completely and fully extend the
boom.
2. Engage auxiliary power.
The elevation angle is sensed by means of a pendulum
potentiometer and the extension of the boom sensed by a
multi-turn potentiometer driven by means of a cable
attached to the telescoping part of the boom. Both of
these sensors are situated at the rear of the base boom
section and housed in a sealed steel box.
3. Engage LIFT DOWN until blue light turns off and red
light turns on. When red light turns on, shut down
machine and check boom angle. Boom angle
should be 64 degrees - 67 degrees. If boom angle is
within this range, the boom angle/length indicator
system is operating properly and requires no further
adjustment. If the boom angle is not within this
range, contact the JLG Service Department for further assistance.
Lift Down Speed Limit Adjustment
1. On lift down speed limit circuit card, measure voltage at TP3. Adjust R1 until 8.0 Volts is obtained.
2. Measure voltage at TP1. Adjust R17 until 3.0 Volts is
obtained.
2.26 LOAD MANAGEMENT SYSTEM
The LMS (Load Management System) consists of three
independent systems.
Platform Position Indication System
This system illuminates one of the two lamps in the platform position display located on both the platform console
and ground control box. A blue light is used to indicate
that the platform is within the permitted operating envelope and a red light is used to indicate when the platform
is outside the permitted operating envelope. Either the
blue or red light should be illuminated at all times.
3120819
The signals from these sensors (elevation angle and
extension distance) are fed into a load radius card which
calculates the boom radius.
Boom Radius = Boom Length x Cos Boom Angle
– JLG Lift –
2-53
SECTION 2 - PROCEDURES
MONITORING
TIMER
RELAYS
TEST SWITCH
RESET SWITCH
MONITOR LATCHING RELAYS
LOAD MOMENT CIRCUIT CARD
LOAD RADIUS CIRCUIT CARD
MONITOR RELAY MODULE
LOAD MOMENT CIRCUIT CARD
Figure 2-25. Control Box Components
This circuit card operates as follows:
A calibrated dc voltage representing the boom angle is
sent from the boom angle sensor to the angle cosine circuit. This voltage is converted to the cosine of the angle
and presented to the radius generator circuit.
A calibrated dc voltage representing the boom length is
sent from the boom length sensor to the boom length circuit and presented to the radius generator circuit.
The length and cosine dc voltages are multiplied together
in the radius generator circuit. The output dc voltage from
this circuit is passed to a radius limiting circuit. This circuit
is set to detect a specific boom radius dimension. The
resultant output signal is sent to a logic network circuit
which determines which of the indicator lamps (blue or
red) should be energized.
Also, when an overmoment condition is sensed by the
overmoment control circuit, a signal is sent to the logic circuit network. This causes either the red or blue lamp to
flash indicating that an overmoment condition exists in
that region. This condition also causes the audible warning to sound at the control consoles.
Overmoment Control System
The turntable is pivoted at the lower front area and compression springs, mounted towards the rear, provide a
reaction force to the moment produced by boom extension. The force produced by the springs is adjusted to balance the moment produced when the boom is extended
to the maximum permitted radius.
There should be a signal from the sensors at all times,
however, if the signal line from the angle, or the boom
length sensor is cut a failure circuit detects this and activates an audible warning horn mounted in the console
panels.
The boom length circuit also produces output dc voltage
when the boom is within a predetermined critical boom
length. This signal energizes a 12 volt dc solenoid flow
control valve (via a relay in the overmoment control circuit
card) to enable the descend function to operate at full
speed. When this signal is removed, the descent function
defaults to a creep speed.
2-54
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Immediately beyond this point of balance the turntable is
permitted to pivot a maximum vertical distance of 3 mm.
This movement is sensed by two independent switches
which power two independent control circuit channels.
1. A positive break mechanical limit switch.
2. An inductive proximity switch.
The monitoring system operates as follows:
There is an output of 12 volts dc at terminal 7 on the overmoment circuit card only after the input at pin No 2 has
received a 12 volt dc signal (from a sensing switch) for a
time duration greater than 3 seconds and this output signal will continue 0.5 seconds after the input signal is
removed.
These input signals also energize two independent 12 volt
timer relays (1 second delay off relay B) which control the
output signals from both circuit cards. If the input is
removed the timer relay B will de-energize after 1 second.
If an output signal from either card remains it will energize
two lockout latching relays (relay C). These relays control
the function signals to lift, lower, and extend the boom.
Therefore, when the latching coils receive a signal the
operator is permitted to retract the platform, to within 3
meters of the fully retracted position. This will enable operation of the boom lower function to bring the platform to
the ground level position. The machine will remain in this
condition (i.e. in the lowered position) until reset by a
competent person.
NOTE: The monitoring system only activates when there is
a malfunction of the overmoment control system.
Load Management System Daily Check
At the beginning of each days’ use, perform check with no
load (persons or material) in platform from ground control
station.
Each circuit channel is arranged as follows:
The switch provides a 12 volt dc signal to a circuit card.
The output from this card energizes a relay which permits
the functional signals for boom extend and descend.
When an input signal to a channel or an output signal
from a circuit card is not present, the lift down and telescope out functions are interlocked.
There is also a warning horn signal present, at both the
platform console and ground box, when either channel is
not energized.
Overmoment Control Monitoring System
The 12 volt dc input signals from the overmoment control
sensing switches are constantly monitored and compared
with the output from the circuit cards by the monitoring
system circuit.
If any fault is detected (input to output on the same channel or input to output on different channels) all movements
of the platform that could increase instability (lift up, lift
down, telescope out) are shut down and the boom permitted to retract and descend in a controlled sequence. The
machine will remain in this state until reset by a competent
person.
3120819
– JLG Lift –
1. Extend all axles fully and insert lock pins (if applicable).
2. With boom fully retracted, raise boom to horizontal.
3. Position toggle switch located on the right side of
the ground control station in the “P” position and
hold.
4. Extend boom until it stops. Boom must stop on
white tape on mid boom. Release toggle switch.
5. Retract boom 3 meters and attempt to extend boom.
boom must not extend. Reset system by activating
toggle switch marked “R” located on right side of
ground control station.
6. Position toggle switch located on the right side of
the ground control station in the “M” position and
hold.
7. Extend boom until it stops. Boom must stop on
white tape on mid boom. Release toggle switch.
8. Retract boom 10 feet (3 meters) and attempt to
extend boom. Boom must not extend. Reset system
by activating toggle switch marked “R” located on
right side of ground control station.
2-55
SECTION 2 - PROCEDURES
Figure 2-26. Boom Length/Angle Sensor Configuration
2-56
– JLG Lift –
3120819
TEST
SWITCH
2
RESET
SWITCH
SECTION 2 - PROCEDURES
Figure 2-27. Load Moment Limiting System Monitoring Circuit
3120819
– JLG Lift –
2-57
SECTION 2 - PROCEDURES
9. If boom does not stop at white tape or boom can be
extended after being retracted 10 feet (3 meters)
without resetting, system must be repaired by JLG
authorized service personnel before machine can be
used.
6. Remove the five (5) bolts and turntable springs from
the turntable.
Installation
1. Position boom to horizontal.
2. Install the five (5) bolts and turntable springs onto
the turntable.
2.27 LOAD MANAGEMENT SYSTEM
ADJUSTMENT
3. Install the five (5) nuts and jam nuts on the turntable
bolts.
1. With boom retracted, limit switch and proximity
switch are in neutral position.
4. Extend boom to cutoff position then retract boom
until turntable raises 0.25 in. (6.4 mm) from cutoff
position, measured at spring area.
2. Extend boom in horizontal position until white tape
on inner mid boom is fully exposed, no load in platform.
5. Snug jam nuts, then fully retract boom.
6. Torque jam nuts to 75 ft. lb. (102 Nm), then tighten
nuts.
3. Adjust proximity switch actuator to trip switch, then
secure locking nut.
7. If removed, install load management switches on
mounting brackets.
4. Adjust proximity switch target until LED just turns on,
then secure locking nut.
8. Position boom to horizontal. Refer to paragraph 2-25
and adjust load management switches as required.
5. To test cutoff switches, retract boom to reset position, then extend boom to test cutoff. Do not extend
boom past white tape.
6. To test limit switch, retract boom to reset, then
extend boom to cutoff while holding test bypass
switch in “M” position. To test proximity switch,
retract boom to reset, then extend boom to cutoff
while holding test bypass switch in “P” position.
When testing switches, do not extend boom past
white tape on inner mid boom.
2.29 DRIVE MOTOR ADJUSTMENT
PROCEDURE
1. Remove the cap nut from adjustment screw.
2. Loosen jam nut on the adjustment screw and make
adjustment.
3. Measure from top of jam nut to the end of adjustment screw. (Figure 2-29., Drive Motor Adjustment)
4. Tighten jam nut, install cap nut.
2.28 TURNTABLE SPRINGS
NOTE: The “o” ring must be seated in groove in cap nut.
Removal
1. Fully retract boom.
2. Remove rear turntable cover.
3. Remove the five (5) nuts and jam nuts from beneath
the turntable which attach to the turntable spring
bolts.
4. If necessary, remove the bolts which secure the load
management switches to the mounting bracket and
allow the switches to hang freely.
WRAP MASKING TAPE AROUND THE LOAD MANAGEMENT
SWITCHES TO INSURE THAT THE SWITCHES WILL STILL BE
OPERABLE.
5. Position boom to horizontal.
2-58
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
Figure 2-28. Load Radius Circuit Card
3120819
– JLG Lift –
2-59
SECTION 2 - PROCEDURES
Figure 2-29. Drive Motor Adjustment
2.30 PREVENTIVE MAINTENANCE AND
INSPECTION SCHEDULE
The preventive maintenance and inspection checks are
listed and defined in the following table. 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" of the table, the various systems
along with 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.
JLG INDUSTRIES REQUIRES THAT A COMPLETE ANNUAL
INSPECTION BE PERFORMED IN ACCORDANCE WITH THE
"ANNUAL MACHINE INSPECTION REPORT" FORM.
This machine requires periodic safety and maintenance
inspections by a JLG Dealer. A decal located on the turntable affords a place to record (stamp) inspection dates.
Notify dealer if inspection is overdue.
The inspection and maintenance code numbers are as follows:
1. Check for proper and secure installation.
2. Check for visible damage and legibility.
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.
3. Check for proper fluid level.
4. Check for any structural damage; cracked or broken
welds; bent or warped surfaces.
5. Check for leakage.
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. Forms must be completed and returned to JLG
Industries.
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.
2-60
– JLG Lift –
3120819
SECTION 2 - PROCEDURES
11. Check for proper operation while engine 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.
15. Check for proper inflation.
16. Clean or replace suction screen.
17. Drain and clean.
* To be performed quarterly.
** Inspection and Maintenance Code 10, 12, 16 to performed every two years.
Table 2-7.Preventive Maintenance and Inspection Schedule
INTERVAL
AREA
DAILY
WEEKLY
MONTHLY
3 MONTH
6 MONTH
YEARLY
BOOM
1.
Platform
1,4
2.
Platform Gate
1,4
3.
Platform Rotator
4.
Footswitch
1,11
5.
Controllers
1,11
6.
Switches
1,11
7.
Placards and Decals
1,2
8.
Control Tags
1,2
9.
Valves
1,11
5,6
10.
Carrier (Hoses and Cables)
1
4,8
12.
Pins
8, 12
13.
Bushings
8, 12
14.
Wear Pads
8, 12
15.
Cylinders
16.
Boom Chain Adjusters
17.
Sheaves
18.
Radius Limit Tape
19.
Drift Test*
3120819
12
5,11
1,5,6,13
8, 12
12
9
8, 12
1, 2
– JLG Lift –
2-61
SECTION 2 - PROCEDURES
Table 2-7.Preventive Maintenance and Inspection Schedule
INTERVAL
AREA
DAILY
WEEKLY
MONTHLY
3 MONTH
6 MONTH
YEARLY
TURNTABLE
1.
Engine Oil (see mfg. manual)
3
5
2.
Battery
3
5
3.
Radiator
4.
Air Cleaner
1
5.
Exhaust System
1
7.
Engine Mount
8.
Ground Controls
9.
Main Hydraulic Pump
1
5
10.
Auxiliary Power Pump
1
5
11.
Valves
1,11
5
12.
Hydraulic Filters
13.
Hydraulic Hoses
1
5
14.
Hydraulic Oil Tank**
3
5
15.
Breather Hydraulic Tank
16.
Fuel Tank
17.
Cylinders
19.
Turntable Locking Pin
1,7
20.
Horizontal Limit Switch
1,7
21.
Oil Coupling
22.
Placards and Decals
Tilt Alarm Switch
23.
Swing Bearing
24.
Swing Brake
25.
Swing Hub
2-62
3, 5
14
1,5
1
1,2,11
5, 14
14
4
6,14
3,5
4
1,5,6,13
4, 12
5
1,2
1, 7
1
1,5,6
1, 3, 5,6
– JLG Lift –
9, 12
8
10
3120819
SECTION 2 - PROCEDURES
Table 2-7.Preventive Maintenance and Inspection Schedule
INTERVAL
AREA
DAILY
WEEKLY
1
8,9,15
MONTHLY
3 MONTH
10
6 MONTH
YEARLY
CHASSIS
1.
Wheel and Tire Assembly
2.
Drive Motors
1,5,6
3.
Drive Torque Hubs
1,5,6
3
4.
Drive Brakes
1,5,6
8
5.
Steer Cylinders
1,5,6,13
12
6.
Steer Components
1
4,6
8, 12
7.
Tie Rod Lock Pin
1
8
8.
Hydraulic Hoses
1
5
9.
Placards and Decals
10.
Wheel Bearings
8
12
11.
Swing Bearing/Worm Gear
12
9
3120819
1,2
– JLG Lift –
2-63
SECTION 2 - PROCEDURES
This page left blank intentionally.
2-64
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
SECTION 3. TROUBLESHOOTING
3.1
GENERAL
This section contains troubleshooting information to be
used for locating and correcting most of the operating
problems which may develop. 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
The troubleshooting procedures applicable to the aerial
platform are listed and defined in Tables 3-1 through 3-6.
As an aid to table use, the aerial platform is divided into
four major groups, each covered separately within this
section. These groups are as follows: elevation system,
chassis assembly, hydraulic system and electrical system.
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 electrical systems. For this reason, every effort has
3120819
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
that 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 (mechanically 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
The reference for improper function of a hydraulic system,
where the cause is not immediately apparent, should be
the Troubleshooting Chart. 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, beginning with the
control, would follow. For aid in troubleshooting, refer to
the Illustrated Parts Manual for hydraulic diagrams of the
various circuits
– JLG Lift –
3-1
SECTION 3 - TROUBLESHOOTING
.
Table 3-1.Platform Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Automatic leveling inoperative.
Hydraulic system oil low.
Replenish oil as necessary.
Dual check valves dirty/inoperative.
Clean or replace as necessary.
Restricted or broken hydraulic line or fitting on
slave cylinder or main lift cylinder.
Clean, repair, or replace line or fitting.
Worn seal(s) in slave level or main lift cylinder.
Replace seal(s).
Counterbalance valve in slave cylinder defective.
Replace counterbalance valve.
Slave level or main lift cylinder not functioning
properly.
Slave level or main lift cylinder not functioning
properly.
Counterbalance valve on slave leveling cylinder
improperly adjusted or not functioning properly.
Replace valve.
Worn seal(s) in slave level or main lift cylinder.
Replace seal(s).
Damaged slave level or main lift cylinder.
Repair or replace cylinder.
Level function not activated within 7 seconds
after footswitch was depressed.
Recycle footswitch.
Level control switch inoperative.
Repair or replace control switch lever.
Hydraulic system oil low.
Replenish oil as necessary.
System orifice plugged/dirty.
Clean orifice.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
No electric to dump or control valve.
See proper wiring diagram.
Slave cylinder not functioning properly.
Repair or replace pump.
Hydraulic pump not functioning properly.
Repair or replace pump.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Slave cylinder not functioning properly.
Repair or replace cylinder.
Electrical failure.
See proper wiring diagram.
Orifice plugged.
Clean orifice.
Platform will not maintain level attitude.
No response to platform leveling controls.
Platform will not adjust "up" or "down" to level.
3-2
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
.
Table 3-2.Boom Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
CONTROL VALVES
Valve spool sticking.
Dirt in oil causing excessive temperature buildup.
Flush system and change oil using recommended viscosity
Moisture in oil.
Flush system and change oil using recommended viscosity
Incorrect valve mounting causing warping of the
unit.
Loosen valve and check mounting. Repair as
necessary.
Valve spool scored.
Remove valve and repair or replace as necessary.
Tie-bolts in valve over torqued.
Correctly torque bolts.
Return spring weak or broken.
Remove valve and repair or replace as necessary.
Relief valve malfunctioning causing excessive
pressure within valve.
Check pressure delivery to and from valve and
repair or replace as necessary.
Dirt or other foreign material under seal.
Remove and repair valve as necessary.
Valve spool scored.
Remove valve and repair or replace as necessary.
Excessive back pressure caused by restricted
return line to reservoir.
Remove line and clear obstruction or replace line
as necessary.
Damaged valve seals.
Remove valve and repair or replace as necessary.
Valve leaking.
BOOM ELEVATION SYSTEM.
No response to lift control switch.
3120819
Lift function not activated within 7 seconds after
footswitch was depressed.
Recycle footswitch.
Lift control switch inoperative.
Repair or replace control switch.
Lift cylinder holding valve inoperative.
Repair or replace holding valve.
Dump valve (bypass) not operating.
Determine cause and repair or replace valve.
Electrical malfunction.
See wiring diagram.
Hydraulic system oil low.
Replenish oil as necessary.
Restricted or broken supply line on valve bank or
hydraulic pump.
Clean or replace line.
– JLG Lift –
3-3
SECTION 3 - TROUBLESHOOTING
Table 3-2.Boom Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Fuse is blown out on control card.
Replace fuse.
Control valve not functioning properly.
Repair or replace valve.
Hydraulic Pump not functioning properly.
Repair or replace pump.
Lift cylinder not functioning properly.
Repair or replace cylinder
Lift function not activated within 7 seconds after
footswitch was depressed.
Recycle footswitch.
Load capacity exceeded (personnel or equipment on platform).
Reduce load.(Refer to capacity placard.)
Hydraulic system oil low.
Replenish oil as necessary.
Electrical failure to valves.
See proper wiring diagram.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Pressure relief valve not functioning properly.
Re-adjust or replace valve.
Bypass valve (dump) not functioning.
Repair or replace valve.
Lift cylinder not functioning properly.
Repair or replace cylinder.
Binding lift cylinder or boom pivot pin.
Repair or replace cylinder or pin.
Boom will not raise.
Boom will not lower.
See: Boom will not raise.
Pressure relief valve not functioning properly.
Re-adjust or replace valve.
Holding valve not functioning properly.
Re-adjust or replace valve.
Hydraulic system oil low.
Replenish oil as required.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Counterbalance valve on lift cylinder improperly
adjusted or not functioning properly.
Replace valve.
Control valve not functioning properly.
Repair or replace valve.
Worn seals in lift cylinder.
Replace seals.
Cylinder not functioning properly.
Repair or replace cylinder.
Worn seals in lift cylinder.
Replace seals.
Boom raises and lowers erratically.
Boom drifts down.
3-4
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
Table 3-2.Boom Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
MAIN TELESCOPE SYSTEM.
No response to telescope control.
Telescope function not activated within 7 seconds after footswitch was depressed.
Recycle footswitch.
Telescope control switch inoperative.
Repair or replace control switch.
Hydraulic system oil low.
Replenish oil as necessary.
Damaged wiring on control switch or solenoid
valve.
Repair or replace wiring.
Control valve not functioning properly.
Repair or replace valve.
Restricted or broken supply line on valve bank or
hydraulic pump.
Clean or replace line.
Telescope cylinder not functioning properly.
Repair or replace cylinder.
Hydraulic pump not functioning properly.
Repair or replace pump.
Telescope function not activated within 7 seconds after footswitch was depressed.
Recycle footswitch.
Control valve not functioning properly.
Repair or replace control valve.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Pressure setting incorrect.
Check pressure/re-adjust as necessary.
Telescope cylinder not functioning properly.
Repair or replace cylinder.
Hydraulic system oil low.
Replenish oil as necessary.
Wear pads worn.
Replace pads as required.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Worn seals in telescope cylinder.
Replace seals.
Cylinder not functioning properly.
Repair or replace cylinder.
Counterbalance valve not functioning properly.
Replace counterbalance valve.
Broken drive chain.
Repair or replace chain.
Broken drive sprocket or bent sprocket shaft.
Replace shaft assembly.
Drive chain out of adjustment.
Adjust chain as required.
Boom will not extend.
Boom extends and retracts erratically.
Fly section inoperative.
Fly section extends and retracts erratically.
3120819
– JLG Lift –
3-5
SECTION 3 - TROUBLESHOOTING
Table 3-2.Boom Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Wear pads out of adjustment or worn.
Adjust or replace pads as required.
Damaged or worn sheave or chain links.
Repair or replace chain or sheave as required.
Fly section distorted.
Replace fly section.
BOOM SWING SYSTEM
No response to swing control.
Swing function not activated within 7 seconds
after footswitch was depressed.
Recycle footswitch.
Hydraulic system oil low.
Replenish oil as necessary.
Swing control switch not functioning.
Repair or replace swing control switch.
Restricted or broken supply line on valve bank or
hydraulic pump.
Clean or replace line.
Control valve not functioning properly.
Repair or replace valve.
Swing motor not functioning properly.
Repair or replace motor.
Restrictor valve(s) plugged.
Clean or replace restrictor valve.
Foreign objects(s) wedged between swing
motor pinion and swing gear.
Remove objects, check for damage, and repair
or replace component(s) as required.
Pressure reducing valve in swing circuit malfunctioning.
Repair or replace pressure reducing valve.
No electric power to valve.
See proper wiring diagram.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Foreign object(s) wedged between swing motor
pinion and swing gear.
Remove object(s), check for damage and repair
or replace component(s) as required.
Swing control switch not functioning properly.
Repair or replace swing control switch.
Hydraulic system oil low.
Replenish oil as necessary.
Lack of lubricant on swing gear or speed reducer
pinion.
Lubricate as required. (See Lubrication Chart.)
Swing motor not functioning properly.
Repair or replace swing control switch.
Worn or broken teeth on swing gear or swing
motor pinion.
Replace gear(s) as required.
Restrictor valves(s) plugged.
Clean or replace restrictor valve.
Boom will swing in one direction only.
Boom swings erratically in either direction.
3-6
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
.
Table 3-3.Turntable Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
CONTROL VALVE.
Valve Spool Sticking.
Dirt in oil causing excessive temperature builtup.
Change oil using recommended viscosity and
flush system.
Incorrect valve mounting causing warping of the
unit.
Loosen valve and check mounting.Repair as
necessary.
Valve spool scored.
Remove valve and repair or replace as necessary.
Return spring weak or broken.
Remove valve and repair or replace as necessary.
Relief valve malfunctioning causing excessive
pressure within valve.
Check pressure delivery to and from valve and
repair or replace as necessary.
Dirt or other foreign material under seal.
Remove and replace valve as necessary.
Valve spool scored.
Repair or replace valve.
Excessive back pressure caused by restricted
return line to reservoir.
Remove line and clear obstruction or replace line
as necessary.
Damaged valve seals.
Repair or replace valve as necessary.
Valve leaking.
3120819
– JLG Lift –
3-7
SECTION 3 - TROUBLESHOOTING
.
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
POWER PLANT.
Engine will not start.
Station power selector switch not in required
position.
Actuate switch as required.
Circuit breaker open.
Determine and correct cause; reset circuit
breaker.
Defective starter motor.
Replace starter motor.
Damaged wiring in ignition circuit (broken wire
on starter).
Repair, replace wiring.
Ignition switch not functioning properly.
Replace switch.
Ignition relay not functioning properly.
Replace relay.
Ignition circuit shorted to ground.
See proper wiring diagram.
Battery cable(s) not making contact.
Clean and tighten cable(s).
Start lockout not working.
See wiring diagram. Check relay.
No fuel.
Replenish fuel as necessary.
Clogged fuel filter.
Replace fuel filter.
Choke solenoid malfunction.
Replace choke solenoid.
Restricted or broken fuel line.
Clean or replace fuel line.
Fuel shut-off valve in carburetor stuck or frozen.
Repair or replace fuel shut-off. Check for electrical power.
Battery discharged.
Charge battery, replace if defective.
Fuel pump not working.
Replace fuel pump.
Cam timing belt jumped time or broken.
Repair or replace timing belt.
Ignition timing slipped.
Repair timing.
Damaged wiring on speed control switch or high
engine solenoid.
Repair or replace wiring.
Drive controller not functioning properly.
Replace controller.
Actuator not functioning properly.
Repair or replace solenoid.
Excessive load on engine.
Reduce load.
Engine worn badly.
Rebuild engine.
Engine will not start (ignition OK).
Engine will not accelerate above low.
3-8
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Engine improperly timed.
Time engine.
Engine overheating.
Determine cause of overheating and remedy.
Dirty fuel filter.
Replace filter.
Fuel line pinched.
Replace fuel line.
Throttle governor not working properly.
Repair or replace governor.
Governor not adjusted properly.
Correctly adjust governor.
Fuel tank overfilled.
Check fuel tank and immediately wipe up spilled
fuel.
Fuel tank damaged.
Drain all fuel from tank and remove tank for
replacement or repair.
Fuel line from tank damaged.
Replace fuel line.
Carburetor flooding.
Repair, replace or adjust carburetor.
Engine surges.
Strong fuel odor.
FRONT FRAME AXLE AREA.
One or both wheels will not steer.
Steering link or tie rod broken or attaching hardware missing.
Replace steering link, tie rod or hardware as necessary.
Wheel hub or bearings damaged or not lubricated.
Replace hub or bearings as necessary and
repack bearings with approved grease.
One or both front wheels will not rotate or
rotate erratically.
REAR FRAME AXLE AREA.
Difficulty encountered when moving
machine.
3120819
Load capacity exceeded.
Reduce load. Apply loads only in accordance
with load capacity indicator.
Flow divider sticking.
Repair or replace flow divider.
Machine being moved up too steep a grade.
Remove machine from grade and check that
drive system operates correctly.
Grade too steep.
See WARNING Placard on platform for specified
grades and sideslopes.
Towing valve not closed.
Close towing valve.
Drive wheel tire treads worn smooth.
Replace tires as necessary and inflate to specified pressure.
– JLG Lift –
3-9
SECTION 3 - TROUBLESHOOTING
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Drive brakes "dragging".
Re-adjust pressure.
System pressure too low.
Re-adjust pressure.
Drive hub(s) defective.
Repair or replace hub.
Engine RPM’s not set.
Correctly set engine RPM.
Drive motors worn.
Repair or replace drive motors.
Counterbalance valve defective.
Replace counterbalance valve.
Low amperage on controller.
Correctly adjust controller.
DRIVE SYSTEM.
No response to control.
Drive function not activated within 7 seconds
after footswitch was depressed.
Recycle footswitch.
Hydraulic system oil low.
Replenish oil as necessary.
Hydraulic pump not functioning properly.
Repair or replace pump.
Restricted or broken pump supply line.
Clean, repair or replace line.
Restricted or broken line on valve bank.
Clean, repair or replace line.
Drive motor(s) not functioning properly.
Repair or replace motor(s).
Air in wheel brake circuit.
Bleed circuit, determine and correct cause.
Fuse is blow-out on control card.
Replace fuse.
Damaged wiring on control switch.
Repair or replace wiring.
Control switch not functioning properly.
Replace switch.
Brake(s) not releasing.
Determine cause and repair or replace.
Hydraulic system oil low.
Replenish oil as necessary.
Restricted or broken hydraulic line or fitting.
Clean, repair or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Drive motor(s) not functioning properly.
Repair or replace motor(s).
Circuit breaker open.
Determine and correct cause; reset circuit
breaker.
Counterbalance valve sticking on return side.
Adjust return counterbalance out 3 turns - cycle
drive - return to original position.
Machine will not travel in forward.
3-10
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Motor turns slowly in the direction of the last command.
Valve not returning to neutral.
Check neutral springs.
Function speed switch malfunction.
Replace function switch.
Sticking spool due to contamination.
Remove end cap and check spool freedom.
Repair as necessary.
Valve spool is not traveling far enough due to:
Repair or replace drive motor(s).
Worn, leaking drive motor(s).
Repair or replace drive motor(s).
Engine RPM’s set too low.
Properly adjust engine RPM’s.
Low control pressure supply.
Replace pressure regulator if necessary.
Function speed switch malfunction.
Replace switch.
Amperage too low on controller.
Correctly adjust controller.
Defective pump, low oil volume.
Repair or replace pump.
Motor turns slowly at maximum command.
Poor response, function shuts off slowly when command is removed.
Low spool spring preload.
Check for correct spring and shims in end caps.
Sticking spool due to contamination.
Remove end cap and check spool freedom.
Ramp set too high in controller.
Adjust controller.
Sticking control handle.
Repair or replace controller.
STEERING SYSTEM.
No response to steer control.
3120819
Hydraulic system oil low.
Replenish oil as necessary.
Hydraulic system pressure too low.
Adjust pressure.
Damaged wiring on control switch or solenoid
valve.
See proper wiring diagram.
Control switch not functioning properly.
Replace switch.
Restricted or broken hydraulic line on valve
bank, hydraulic pump or rotary coupling. (If
equipped.)
Clean, repair or replace line.
If equipped, swivel coupling leaking internally.
(Seals defective.)
Repair or replace coupling.
Steer control valve not functioning properly.
Repair or replace valve.
Steer cylinder not functioning properly.
Repair or replace cylinder.
– JLG Lift –
3-11
SECTION 3 - TROUBLESHOOTING
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Machine hard to steer or steering is erratic.
Hydraulic system oil low.
Replenish oil as necessary.
Restricted hydraulic line or fitting.
Clean, repair or replace line or fitting.
Restricted crossover relief valve.
Clean or replace valve.
Steer system pressure low.
Adjust pressure.
Bent linkage (tie rods).
Repair or replace linkage as required.
Hydraulic pump not functioning properly.
Repair or replace pump.
Steer cylinder not functioning properly.
Repair or replace cylinder.
Damaged wiring on control switch or solenoid
valve.
See proper wiring diagram.
Solenoid valve not functioning properly.
Repair or replace valve.
Control switch not functioning properly.
Replace switch.
Relief valve improperly set or not functioning
properly.
Reset, repair or replace valves as required.
Steer cylinder not functioning properly.
Repair or replace cylinder.
Wiring on control switch is damaged.
See proper wiring diagram.
Wiring on solenoid valve damaged.
Repair or replace wiring.
Coil in solenoid damaged.
Replace coil.
No oil flow or pressure to steer circuit.
Take pressure reading at steer valve and adjust
as necessary.
Bent cylinder rod.
Repair or replace cylinder.
Damaged tie rod.
Replace tie rod.
Crossover relief valve sticking.
Repair crossover relief valve.
Cylinder packing defective.
Repair or replace cylinder.
Steering inoperative.
Machine will not steer left or to the right.
3-12
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
Table 3-4.Chassis Assembly - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Machine wanders; steering not firm.
3120819
Crossover relief valve set too low or not functioning properly.
Reset, repair or replace valve as required.
Steer linkages loose.
Tighten linkage.
Steer wheel toe-in not set properly.
Adjust toe-in for 1/4 inch overall.
Spindle bushings badly worn.
Replace bushings.
– JLG Lift –
3-13
SECTION 3 - TROUBLESHOOTING
.
Table 3-5.Hydraulic System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
HYDRAULIC SYSTEMS - GENERAL.
Hydraulic pump noisy.
Air entering system through broken line or fitting.
(Suction Side.)
Repair or replace line or fitting.
Suction screen dirty.
Clean suction screen.
Air bubbles in oil. (Reservoir oil too low.
Replenish oil as required.
Suction hose squeezed shut.
Determine cause and repair.
Oil filter dirty.
Replace hydraulic filter.
Wrong type of hydraulic oil.
Replace hydraulic oil.
Restricted suction line.
Clean, repair, or replace line.
Restricted reservoir air vent.
Clean or replace vent.
Oil viscosity too high.
Drain system and replace with recommended oil.
(Refer to Hydraulic Oils.)
Air leak in suction side of tank.
Repair leak.
Restricted suction strainer.
Clean strainer.
Oil viscosity too high.
Drain system and replace with recommended oil.
(Refer to Hydraulic Oils.)
Bypass valve not operating properly.
Repair or replace valve.
Main relief valve set too low.
Reset valve as required.
Hydraulic system oil low.
Replenish oil as necessary.
Port relief set too high.
Reset valve as required.
Restricted or blocked return line.
Repair or replace line.
Pump cavitating. (Vacuum in pump due to oil
starvation.)
System overheating.
3-14
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
Table 3-5.Hydraulic System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Pump not delivering oil.
Restricted suction line.
Clean, repair, or replace line.
Air entering system through broken line or fitting.
Repair or replace line or fitting.
Broken pump drive shaft/pump coupling.
Repair or replace pump/pump coupling.
Note: Any time pump or pump drive coupling
is removed coat pump and drive coupling
splines with Lithium Soap Base Grease (TEXACO CODE 1912 OR EQUIVALENT).
Function sluggish during operation. (System pressure too low.)
Main relief valve set too low.
Reset valve as required.
Pump section not delivering sufficient oil.
Repair or replace pump section or pump.
Main relief valve stuck in open position.
Clean, repair, or replace valve. (Check system oil
for contamination.)
Oil viscosity too low.
Drain system and replace with recommended oil.
(Refer to Hydraulic Oils.)
Leak in component, line or fitting.
Repair or replace component, line or fitting.
Scored valve spool; scored cylinder.
Replace valve; replace cylinder.
Amperage too low on controller.
Correctly adjust controller.
Low sequence pressure.
Reset valve as required.
Low pilot pressure.
Reset valve as required.
Wrong/defective spool in drive section.
Repair or replace drive section.
Shuttle balls leaking in proportional valve.
Repair or replace valve.
Low voltage in electrical system.
Correct low voltage problem.
Sticking or binding valve spools, pistons.
Clean, repair, or replace components as
required.
System(s) operate erratically.
AUXILIARY HYDRAULIC SYSTEM.
Auxiliary hydraulic pump inoperable.
3120819
Circuit breaker open.
Determine and correct cause; reset circuit
breaker.
Engine is running.
Shut down engine.
Check valve in system leaking.
Repair or replace check valve.
Battery requires charging or will not hold a
charge.
Charge or replace battery as required.
– JLG Lift –
3-15
SECTION 3 - TROUBLESHOOTING
Table 3-5.Hydraulic System - Troubleshooting
TROUBLE
3-16
PROBABLE CAUSE
REMEDY
Damaged wiring on control switch or auxiliary
pump.
See proper wiring diagram.
Control switch not functioning properly.
Replace switch.
Restricted or broken hydraulic line or fitting.
Clean, repair or replace line or fitting.
Pump motor solenoid not functioning properly.
Replace solenoid.
Pump motor not functioning properly.
Repair or replace motor.
– JLG Lift –
3120819
SECTION 3 - TROUBLESHOOTING
.
Table 3-6.Electrical System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
PLATFORM CONTROLS.
No power to platform controls.
Self-reset circuit breaker open.
Check footswitch to ensure that both switches
are making contact when pedal is depressed.
Repair or replace footswitch as necessary.
Contact block in footswitch malfunctioning.
Repair, replace or adjust contact block as
required.
Faulty power circuit wiring.
Check wiring continuity. Refer to proper wiring
diagram.
Select switch in wrong position.
Place select switch to correct position.
ENGINE STARTER SYSTEM.
Starter will not crank.
Discharged battery or loose battery terminals.
Check and charge battery or replace battery as
necessary. Clean and secure battery terminals.
Starter relay faulty or faulty relay connections.
Using a test meter, check relay coil terminals for
presence of electrical power and for energization
of relay coil. Also check relay terminals for correct switching of contacts. Replace relay as necessary.
Malfunctioning starter solenoid or motor.
Replace solenoid or motor in accordance with
applicable manufacturer’s manual.
Malfunctioning ignition switch.
Using a test meter, check ignition switch for correct switching of contacts. Replace switch as
necessary.
Faulty ignition and/or starter circuit wiring.
Check wiring continuity. See proper wiring diagram.
Faulty start lockout system.
See correct wiring diagram.
Faulty start switch.
Replace switch.
Faulty ignition and/or starter circuit wiring.
Check wiring continuity. See proper wiring diagram.
Malfunctioning starter solenoid or motor.
Replace solenoid or motor in accordance with
applicable manufacturer’s manual.
Faulty start switch.
Replace switch.
Engine continues to crank.
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SECTION 3 - TROUBLESHOOTING
Table 3-6.Electrical System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
INSTRUMENTS AND INDICATORS.
Travel warning horn inoperative.
Damaged wiring in horn circuit.
Repair or replace wiring.
Damaged horn.
Replace horn.
Damaged wiring in hourmeter circuit.
Repair or replace wiring.
Defective pressure switch.
Replace pressure switch.
Inoperative hourmeter.
Replace hourmeter.
Damaged wiring in hourmeter circuit.
Repair or replace wiring.
Defective pressure switch.
Replace pressure switch.
Inoperative hourmeter.
Replace hourmeter.
Damaged wiring in tilt alarm circuit.
Repair or replace wiring. See proper wiring diagram.
Tilt alarm inoperative.
Replace tilt alarm.
Tilt alarm not adjusted properly.
Adjust tilt alarm.
Defective bulb in tilt light.
Replace bulb.
Switch damaged or inoperative.
Replace switch.
Damaged or disconnected wiring in circuit.
Repair or replace wiring.
Defective pump section.
Repair or replace pump section.
Electrical malfunction.
See correct wiring diagram.
Hourmeter inoperative.
Hourmeter inoperative.
Tilt alarm circuit.
Wheel motor speed circuit.
PQ HAND CONTROLLER.
Actuation of a function of the valve continues when the handle is in the center position
3-18
Improper null of the handle with the control handle safety deadman switch failed.
Check safety deadman switch and replace if necessary. Re-adjust the null of the handle.
Improper null of the handle with the handle safety
deadman switch failed.
Check the safety deadman switch and replace.
Re-adjust the null of the potentiometer.
Too much ramp in controller.
Adjust ramp as needed.
Microswitch in controller bad.
Replace microswitch
Controller improperly adjusted.
Adjust controller.
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SECTION 3 - TROUBLESHOOTING
Table 3-6.Electrical System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Regardless of which way handle is moved, only one function occurs.
Improper wiring or loose wiring to the solenoids
or potentiometer.
Check all wiring for proper connections.
Printed circuit board failure.
Replace printed circuit board or use a handle
assembly from a circuit that is presently working
to check valve.
Potentiometer needs adjusted.
Adjusted potentiometer as required.
Spool stuck in valve bank.
Clean/replace spool.
Function occurs very rapidly when handle is moved in one direction and very slowly when moved in the opposite direction.
Improper null of the handle.
Check and re-adjust null.
Potentiometer off-center.
Center potentiometer.
Defective printed circuit board.
Replace printed circuit board.
Valve will not function when handle is moved in either direction.
No electrical power to handle.
Check electrical input to handle (12V).
No electrical signal to valve.
Check electrical valve output of printed circuit
board and electrical signal at the valve. Repair or
replace wiring or circuit board as necessary.
Failed printed circuit handle.
Replace square wave generator or use a handle
assembly that is presently working in the system.
Failed open control handle safety deadman
switch.
Check and replace deadman switch.
Improper ground.
Check for proper grounding of handle.
Failed microswitch.
Replace microswitch.
No pilot oil at valve.
Check pressure reducing valve and adjust if
needed.
No sequence pressure at valve.
Check pressure reducing valve and adjust as
needed.
No oil volume at valve bank.
Check pump for failure.Check hydraulic oil level.
Failed or stuck port relief.
Clean or replace port relief.
Functions occur in the opposite direction than required in regard to handle movement.
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Valve coils are reversed.
Reverse control valve coils.
Coil wires are reversed.
Reverse coil wires.
Hydraulic hoses reversed.
Refer to hydraulic diagram for proper hosing.
– JLG Lift –
3-19
SECTION 3 - TROUBLESHOOTING
Table 3-6.Electrical System - Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Abrupt start-up of any functions: both directions.
Card “Low” potentiometer setting too high.
Adjust “Low” potentiometer to “Just Start” function.
“High” and “Low” pots set too close together.
Adjust per JLG Publication 3120351.
Slow function speed/engine lugs down at full throttle position.
Card “High” potentiometer set too low.
Adjust “High” potentiometer until function speed
does not lug down.
“High” and “Low” pots not adjusted properly.
Adjust pots to factory specifications or refer to
JLG Publication 3120351 for proper adjustment.
Speed not proportional.
Cylinder drifts or drive motor slowly rotates when controller is returned to neutral. (high null bias)
3-20
Controller failed, resulting in a command at neutral position.
Adjust or replace microswitch.
Microswitch remained open in controller.
Replace microswitch.
Ramp too high in controller.
Set ramp as needed.
Brakes not applying in swing or drive.
Check brakes. Repair or replace as necessary.
– JLG Lift –
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SECTION 3 - TROUBLESHOOTING
Figure 3-1. Electrical Diagram - Boom Length Indicator
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SECTION 3 - TROUBLESHOOTING
Figure 3-2. Electrical Schematic - CE - Sheet 1 of 4
3-22
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SECTION 3 - TROUBLESHOOTING
1870088A
Figure 3-3. Electrical Schematic - CE - Sheet 2 of 4
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SECTION 3 - TROUBLESHOOTING
Figure 3-4. Electrical Schematic - CE - Sheet 3 of 4
3-24
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SECTION 3 - TROUBLESHOOTING
1870088A
Figure 3-5. Electrical Schematic - CE - Sheet 4 of 4
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SECTION 3 - TROUBLESHOOTING
Figure 3-6. Hydraulic Schematic - (Sheet 1 of 2)
3-26
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SECTION 3 - TROUBLESHOOTING
2792377A
Figure 3-7. Hydraulic Schematic - (Sheet 2 of 2)
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SECTION 3 - TROUBLESHOOTING
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3-28
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Corporate Office
JLG Industries, Inc.
1 JLG Drive
McConnellsburg PA. 17233-9533
USA
Phone: (717) 485-5161
Fax: (717) 485-6417
JLG Worldwide Locations
JLG Industries (Australia)
P.O. Box 5119
11 Bolwarra Road
Port Macquarie
N.S.W. 2444
Australia
Phone: (61) 2 65 811111
Fax: (61) 2 65 810122
JLG Industries (UK)
Unit 12, Southside
Bredbury Park Industrial Estate
Bredbury
Stockport
SK6 2sP
England
Phone: (44) 870 200 7700
Fax: (44) 870 200 7711
JLG Deutschland GmbH
Max Planck Strasse 21
D-27721 Ritterhude/lhlpohl
Bei Bremen
Germany
Phone: (49) 421 693 500
Fax: (49) 421 693 5035
JLG Industries (Italia)
Via Po. 22
20010 Pregnana Milanese - MI
Italy
Phone: (39) 02 9359 5210
Fax: (39) 02 9359 5845
JLG Latino Americana Ltda.
Rua Eng. Carlos Stevenson,
80-Suite 71
13092-310 Campinas-SP
Brazil
Phone: (55) 19 3295 0407
Fax: (55) 19 3295 1025
JLG Europe B.V.
Jupiterstraat 234
2132 HJ Foofddorp
The Netherlands
Phone: (31) 23 565 5665
Fax: (31) 23 557 2493
JLG Industries (Norge AS)
Sofeimyrveien 12
N-1412 Sofienyr
Norway
Phone: (47) 6682 2000
Fax: (47) 6682 2001
JLG Polska
UI. Krolewska
00-060 Warsawa
Poland
Phone: (48) 91 4320 245
Fax: (48) 91 4358 200
JLG Industries (Europe)
Kilmartin Place,
Tannochside Park
Uddingston G71 5PH
Scotland
Phone: (44) 1 698 811005
Fax: (44) 1 698 811055
JLG Industries (Pty) Ltd.
Unit 1, 24 Industrial Complex
Herman Street
Meadowdale
Germiston
South Africa
Phone: (27) 11 453 1334
Fax: (27) 11 453 1342
Plataformas Elevadoras
JLG Iberica, S.L.
Trapadella, 2
P.I. Castellbisbal Sur
08755Castellbisbal
Spain
Phone: (34) 93 77 24700
Fax: (34) 93 77 11762
JLG Industries (Sweden)
Enkopingsvagen 150
Box 704
SE - 175 27 Jarfalla
Sweden
Phone: (46) 8 506 59500
Fax: (46) 8 506 59534