JLG G6-42A Service Manual - Manual (Page 52)

Boom
3-14 G6-42A, G9-43A, G10-43A
18. Install the previously removed strong back (16) with
the existing hardware. Torque as required.
19. Install the extend/retract cylinder pin (17) through the
strong back (16). Secure the pin with the retaining
rings.
20. Apply CAT Thread Lubricant to the extend chain
clevis rod threads (18).
21. Install the extend chain clevis rod (18) into the strong
back (16).
22. Install the belleville washers (19) as previously
removed (cupped washer facing strong back). Install
the adjustment nut and lock nut. Snug, but Do Not
tighten at this time.
23. Remove the caps and plugs from the extend/retract
cylinder fittings and the extend/retract tubes (20).
24. Install both extend/retract tubes (20) and torque as
required.
25. Uncap and reconnect the previously labeled
hydraulic hoses to the extend/retract cylinder.
26. Uncap and connect and remaining hydraulic fittings
to their appropriate locations.
27. Recheck wear pad gaps to ensure they meet the
minimum gap requirement. Shim if necessary.
28. Ensure that the boom chains are properly adjusted.
Refer to Section 3.8, “Boom Adjustments.”
29. Properly connect the battery.
30. Start the engine and operate all boom functions
several times. Check for leaks, and check the
hydraulic fluid level in the reservoir; add fluid if
required.
31. Clean up all debris, hydraulic fluid, etc., in, on, near
and around the machine.
32. Close and secure the engine cover.
33. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
3.6 EXTEND/RETRACT CHAIN
REMOVAL/INSTALLATION
3.6.1 Extend/Retract Chain Removal
The following section explains the removal of the extend/
retract chains without removing or disassembling the
boom assembly.
1. Park the machine on a hard, level surface, level the
machine, fully retract the boom, level the boom,
place the transmission control lever in
(N) NEUTRAL, engage the park brake and shut the
engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
3. Open the engine cover. Allow the system fluids to
cool.
4. Properly disconnect the battery.
5. Remove the cover from the rear of the first boom
section.
6. Remove the extend/retract cylinder hydraulic
tubes (4). Plug the tube ends and cap the fittings to
keep dirt & debris from entering the hydraulic
system.
7. Remove the extend/retract cylinder mounting pin (5)
from the strong back.
MAL2660
18
20 20
17
16
19
G6-42A
G9-43A
G10-43A
MY0580
5
4
6