Service Manual

SECTION 4 - BOOM & PLATFORM
3121202 – JLG Lift – 4-3
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.
Eight 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.
4.4 BOOM MAINTENANCE
Removal
1. Remove the platform/support as follows:
a. Disconnect electrical cable from control con-
sole.
b. Remove the eight (8) bolts securing the platform
to the platform support, then remove the plat-
form.
c. Using an overhead crane or suitable lifting
device, strap support the platform support.
d. Remove the six (6) bolts and locknuts securing
the support to the rotator.
e. Using a suitable brass drift and hammer, remove
the rotator shaft, then remove the support from
the rotator.
2. Remove the rotator and slave level cylinder from the
fly boom as follows:
a. Tag and disconnect hydraulic lines to rotator.
Use suitable container to retain any residual
hydraulic fluid. Cap hydraulic lines and ports.
b. Remove hardware from pin #1. Using a suitable
brass drift and hammer remove pin #1 from the
fly boom.
c. Supporting the rotator, remove the hardware
from pin #2. Using a suitable brass drift and
hammer, remove pin #2 from the fly boom and
remove the rotator.
d. Telescope the fly section out approximately 20
inches (50.8 cm) to gain access to the slave lev-
eling cylinder.
e. Supporting the slave, cylinder remove the hard-
ware from pin #3. Using a suitable brass drift
and hammer remove pin #3 from the fly boom.
f. Tag and disconnect hydraulic lines to the slave
leveling cylinder. Use a suitable container to
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.
Figure 4-4. Location of Components - Platform Support