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
0.004
0.10
9
228.6
0.003
0.08
NOTE:
This information is based on 6 drops per minute cylinder
leakage.
SECTION 2 - GENERAL
31215031
2-5
Cylinder Thermal Drift
The oil in all hydraulic cylinders will expand or contract due to
thermal effects over time and may result in changes to the
boom and/or platform position while the machine is station-
ary. These effects occur as the cylinder oil changes tempera-
ture, usually from a higher oil temperature as it cools and
approaches the ambient air temperature. Results of these
effects are related to several factors including cylinder length
and change in temperature over the time the cylinder remains
stationary.
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 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 housing.
d.
Debris embedded in liner surface.
3.
Pins should be replaced if any of the following is
observed (Clean pin before inspection):
a.
Detectable bearing area wear.
b.
Flaking, peeling, scoring, or scratches on pin surface.
c.
Rusting of pin in 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 lubricated unless
otherwise instructed (i.e. sheave pins).
c.
Pins should be inspected to ensure it is free of burrs,
nicks, and scratches which would damage the bear-
ing during installation and operation.
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 battery.
• Disconnect 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 chassis.
• Ground on turntable and weld on any other area than turn-
table.
• Ground on platform/support and weld on any other area
than 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 grounding
position and welded area.
FAILURE TO COMPLY WITH THESE INSTRUCTIONS MAY RESULT IN COMPO-
NENT DAMAGE (I.E. ELECTRONIC MODULES, SWING BEARING, COLLECTOR
RING, BOOM WIRE ROPES ETC.).
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