JLG 3246ES Service Manual - Manual (Page 33)

SECTION 2 - GENERAL
3121166 – JLG Lift – 2-5
2.4 CYLINDER DRIFT TEST
Maximum acceptable cylinder drift is to be measured
using the following methods.
Platform Drift
Measure the drift of the platform to the ground. Fully
elevate the platform. Maximum allowable drift is 2
inches (5 cm) in 10 minutes. If the machine does not
pass this test, proceed with the following.
Cylinder Drift
Drift is to be measured at the cylinder rod with a cali-
brated dial indicator. The cylinder oil must be at ambi-
ent temperature and temperature stabilized.
The cylinder must have the normal load, which is the
normal 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 opera-
tion.
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
housing.
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 hous-
ings must be free of all contamination.
b. Bearing/pins should be cleaned with a solvent
to remove all grease and oil...filament wound
bearings are dry joints 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.
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