Table of Contents
Advertisement
Cylinder Leakage Test
Cylinder oil must be at stabilized ambient temperature
before beginning this test.
Measure drift at cylinder rod with a calibrated dial indicator.
In an area free of obstructions, cylinder must have load
applied and appropriately positioned to detect drift.
Cylinder leakage is acceptable if it passes this test.
Table 2-2. Cylinder Drift
Cylinder Bore Diameter
inches
mm
3
76.2
3.5
89
4
101.6
5
127
6
152.4
7
177.8
8
203.2
9
228.6
NOTE: This information is based on 6 drops per minute cylinder
leakage.
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 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 housing.
31215019
Max. Acceptable Drift
in 10 Minutes
inches
mm
0.026
0.66
0.019
0.48
0.015
0.38
0.009
0.22
0.006
0.15
0.005
0.13
0.004
0.10
0.003
0.08
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 sur-
face.
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 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 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, COL-
LECTOR RING, BOOM WIRE ROPES ETC.)
SECTION 2 - GENERAL
2-5
Advertisement
Table of Contents
