JLG 680S Service Manual - Manual (Page 41)

SECTION 2 - GENERAL
3121234 – JLG Lift – 2-5
Cylinder Drift
Drift is to be measured at the cylinder rod with a calibrated
dial indicator. The cylinder oil must be at ambient temper-
ature and temperature stabilized.
The cylinder must have the normal load, which is the nor-
mal platform load applied.
If the cylinder passes this test, it is acceptable.
NOTE: This information is based on 6 drops per minute cyl-
inder leakage.
2.5 PINS AND COMPOSITE BEARING REPAIR
GUIDELINES
Filament wound bearings.
1. Pinned joints should be disassembled and
inspected if the following occurs:
a. Excessive sloppiness in joints.
b. Noise originating from the joint during operation.
2. Filament wound bearings should be replaced if any
of the following is observed:
a. Frayed or separated fibers on the liner surface.
b. Cracked or damaged liner backing.
c. Bearings that have moved or spun in their hous-
ing.
d. Debris embedded in liner surface.
3. Pins should be replaced if any of the following is
observed (pin should be properly cleaned prior to
inspection):
a. Detectable wear in the bearing area.
b. Flaking, pealing, scoring, or scratches on the pin
surface.
c. Rusting of the pin in the bearing area.
4. Re-assembly of pinned joints using filament wound
bearings.
a. Housing should be blown out to remove all dirt
and debris...bearings and bearing housings
must be free of all contamination.
b. Bearing / pins should be cleaned with a solvent
to remove all grease and oil...filament wound
bearing are a dry joint and should not be lubri-
cated.
c. Pins should be inspected to ensure it is free of
burrs, nicks, and scratches which would dam-
age the bearing during installation and opera-
tion.
2.6 WELDING ON JLG EQUIPMENT
NOTE: This instruction applies to repairs, or modifications to
the machine and to welding performed from the
machine on an external structure, or component,
Do the Following When Welding on JLG
Equipment
• Disconnect the battery.
• Disconnect the moment pin connection (where fitted)
• Ground only to structure being welded.
Do NOT Do the Following When Welding on
JLG Equipment
• Ground on frame and weld on any other area than the
chassis.
• Ground on turntable and weld on any other area than
the turntable.
• Ground on the platform/support and weld on any other
area than the platform/support.
• Ground on a specific boom section and weld on any
other area than that specific boom section.
• Allow pins, wear pads, wire ropes, bearings, gearing,
seals, valves, electrical wiring, or hoses to be between
the grounding position and the welded area.
FAILURE TO COMPLY WITH THE ABOVE REQUIREMENTS MAY
RESULT IN COMPONENT DAMAGE (I.E. ELECTRONIC MODULES,
SWING BEARING, COLLECTOR RING, BOOM WIRE ROPES ETC.)
Table 2-2. Cylinder Drift
Cylinder Bore Diameter
Max. Acceptable Drift
in 10 Minutes
inches mm inches mm
3 76.2 0.026 0.66
3.5 89 0.019 0.48
4 101.6 0.015 0.38
5 127 0.009 0.22
6 152.4 0.006 0.15
7 177.8 0.005 0.13
8 203.2 0.0038 0.10
9 228.6 0.0030 0.08