JLG 660SJ Service Manual - Manual (Page 109)

SECTION 4 - BOOM & PLATFORM
3120840 – JLG Lift – 4-7
3. Remove the powertrack from the boom as follows:
a. Disconnect wiring harness from ground control
box.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
b. Tag and disconnect hydraulic lines from boom
to control valve. Use a suitable container to
retain any residual hydraulic fluid. Cap hydraulic
lines and ports.
c. Disconnect the dual capacity indicator limit
switch from side of boom section.
d. Remove hydraulic lines and electrical cables
from powertrack.
e. Using a suitable lifting equipment, adequately
support powertrack weight along entire length.
f. Remove bolts #1 securing the push tube on the
fly boom section.
g. Remove bolts #2 securing the push tube on the
mid boom section.
h. With powertrack support and using all applica-
ble safety precautions, remove bolts #3 and #4
securing rail to the base boom section. Remove
powertrack from boom section.
4. Remove boom assembly from machine as follows:
a. Using suitable lifting equipment, adequately
support boom assembly weight along entire
length.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
b. Tag and disconnect hydraulic lines from tele-
scope cylinder. Use a suitable container to retain
any residual hydraulic fluid. Cap hydraulic lines
and ports.
c. Disconnect wire to the proximity switch on the
aft end of the boom assembly.
d. Remove hardware securing the lift cylinder rod
end to the base boom section.
e. Using a suitable brass drift and hammer, remove
the lift cylinder pin from the base boom.
f. Remove hardware securing the master cylinder
rod end to the base boom section.
g. Using a suitable brass drift and hammer, remove
the master cylinder pin from the base boom.
h. Remove hardware securing the pushbar to the
turntable upright.
WHEN REMOVING PIN FROM PUSHBAR. CARE MUST BE TAKEN
NOT TO DROP THE PUSHBAR ONTO THE WIRE ROPE ADJUST-
MENT THREADS. FAILURE TO DO SO WILL RESULT IN DAMAG-
ING THREADS.
i. Using a suitable brass drift and hammer, remove
the push bar pin from the turntable upright.
j. Remove hardware securing the boom pivot pin
to the turntable upright.
k. Using a suitable brass drift and hammer, remove
the pivot pin from the turntable upright.
l. Using all applicable safety precautions, carefully
lift boom assembly clear of turntable and lower
to ground or suitably supported work surface.
Figure 4-9. Location of Components - Boom Powertrack