Service Manual Owner's manual

SECTION 4 - BOOM & PLATFORM
3121139 – JLG Lift – 4-19
4.2 WIRE ROPE
Each day before using the machine:
1. Raise the main boom to approximately horizontal.
2. Extend and retract the boom sections.
3. Check for delayed movement of the fly section,
which indicates loose wire ropes.
Inspection
NOTE: The pictures in this paragraph are just samples to
show the replacement criteria of the rope.
1. Inspect ropes for broken wires, particularly valley
wire breaks and breaks at end terminations.
2. Inspect ropes for corrosion.
3. Inspect ropes for kinks or abuse.
4. Inspect sheaves for condition of bearings/pins. (See
Dimension Of Sheaves for proper dimension.)
5. Inspect sheaves for condition of flanges. (See
Dimension Of Sheaves for proper dimension.)
6. Inspect sheaves with a groove wearout gauge for
excessive wear.
7. Ropes passing inspection should be lubricated with
wire rope lubricant before reassembly.
Three Month Inspection
1. Remove boom covers and visually (with flashlight)
inspect the ropes for rust, broken wires, frays,
abuse, or any signs of abnormalities.
2. Check rope tension by deflecting the ropes by
hand...properly tensioned ropes should have little or
no movement.
Seven Year Inspection
1. Mandatory wire rope and sheave replacement.
Additional inspection required if:
a. Machine is exposed to hostile environment or
conditions.
b. Erratic boom operation or unusual noise exists.
c. Machine is idle for an extended period.
d. Boom is overloaded or sustained a shock load.
e. Boom exposed to electrical arc...wires may be
fused internally.
Replacement Criteria
1. Sheaves and wire rope must be replaced as sets.
2. Rusted or corroded wire ropes.
3. Kinked, “bird caged”, or crushed ropes.
4. Ropes at end of adjustment range.
5. Sheaves failing wearout gage inspection.
6. Ropes with 6 total broken wires in one rope lay, 3 in
one strand in one rope lay, 1 valley break, or 1 break
at any end termination.
Flexing a wire rope can often expose broken wires
hidden in valleys between strands.
A kink is caused by pulling down a loop
in a slack line during improper handling,
installation, or operation.
Observe the groove so that it may be clearly seen
whether the contour of the gauge matches the
contour of the bottom of the groove.