Service Manual Manual

SECTION 4 - BOOM & PLATFORM
4-20 – JLG Lift – 3120840
Assembly
NOTE: For location of components See Section 4-23., Loca-
tion of Components - Articulating Jib Boom.
1. Align lift cylinder with attach holes in articulating jib
boom. Using a soft head mallet, install cylinder pin
#7 into articulating jib boom and secure with mount-
ing hardware.
2. Align rotator support with attach hole in articulating
jib boom. Using a soft head mallet, install rotator
support pin #6 into articulating jib boom and secure
with mounting hardware.
3. Align bottom tubes with attach holes in rotator sup-
port. Using a soft head mallet, install rotator support
pin #5 into articulating jib boom and secure with
mounting hardware.
4. Align articulating jib boom with attach hole in articu-
lating jib boom pivot weldment. Using a soft head
mallet, install rotator support pin #4 into articulating
jib boom and secure with mounting hardware.
5. Align bottom tubes with attach holes in articulating
jib boom pivot weldment. Using a soft head mallet,
install rotator support pin #3 into articulating jib
boom pivot weldment and secure with mounting
hardware.
6. Align articulating jib boom pivot weldment with
attach holes in fly boom assembly. Using a soft head
mallet, install pivot pin #2 into fly boom assembly
and secure with mounting hardware.
7. Align the slave leveling cylinder with attach holes in
articulating jib boom pivot weldment. Using a soft
head mallet, install slave leveling cylinder pin #1
into articulating jib boom pivot weldment and secure
with mounting hardware.)
Main Boom Telescope Cylinder Removal
8. Place machine on a flat and level surface, with main
boom in the horizontal position.
9. Shut down engine. Support main boom basket end
with a prop. See Figure 4-24., Boom Positioning and
Support, Cylinder Repair (S Models).
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID THE ENTRY OF
CONTAMINANTS INTO THE SYSTEM.
10. Tag and disconnect hydraulic lines to telescope cyl-
inder. Use a suitable container to retain any residual
hydraulic fluid. Cap hydraulic lines and ports.
11. Remove the hardware securing cover plate on bot-
tom of the base boom section and remove cover.
NOTE: Do not allow cable to rotate. This may damage the
cable.
12. Clamp both threaded ends of cable to prevent rota-
tion. Note: Do not clamp on threads. Remove jam
nuts and loosen adjustment nuts so there is slack in
the cables. (See Figure 4-2., Clamping Wire Ropes).
13. Remove the hardware securing push bar to turnta-
ble and telescope cylinder.
14. Using a suitable brass drift, carefully drive the push
bar pins from the telescope cylinder rod and turnta-
ble.
15. Remove hardware securing cable adjustment block
to aft end of the base boom section and remove
block.
Figure 4-24. Boom Positioning and Support, Cylinder Repair (S Models)