JLG G6-42A Service Manual - Manual (Page 56)

Boom
3-18 G6-42A, G9-43A, G10-43A
15. Loosen and remove four bolts (12), guide bar (13)
and chain retainer (14) from front of push beam.
16. Disconnect extend chain (15) from anchor rod (16)
and lay flat on bottom of third boom section. Remove
anchor rod (16) from front of boom.
Note: It may be necessary to lift the extend /retract
cylinder through the access holes in the sides of the third
boom section to remove the chain retainer (14).
17. At rear of boom, remove both retaining clips (17)
from extend/retract cylinder pin (18). Remove
extend/retract cylinder pin from strong back (19).
18. Loosen and remove eight bolts (20) from the strong
back (19). Remove strong back.
19. Remove both extend/retract cylinder hydraulic tubes.
Plug tube ends and cap the fittings to prevent dirt
and debris from entering hydraulic system.
20. Place a sling around push beam—extend/retract
cylinder assembly. Lift and slowly pull push beam—
extend/retract cylinder assembly approximately half
way out the front of boom assembly.
21. Lower push beam onto a suitable support.
22. Relocate sling or using two slings for better stability,
balance push beam extend/retract cylinder assembly
and slowly pull push beam extend/retract cylinder
assembly out towards the front of boom assembly.
23. Lower the push beam extend/retract cylinder
assembly onto suitable supports.
24. Remove the extend/retract cylinder as required.
3.7.2 Push Beam — Extend/Retract
Cylinder Installation
1. Clean and lubricate bottom and sides of third boom
section where push beam guide bar travels.
2. Place a sling or using two slings for better stability,
lift and slowly push the push beam—extend/retract
cylinder assembly approximately half way into the
front of the boom assembly.
3. Lower the push beam onto a suitable support.
4. Relocate the sling and slowly insert the push
beam—extend/retract cylinder assembly into the
front of the boom assembly.
5. Remove the plugs and caps from extend/retract
cylinder hydraulic tubes. Install both extend/retract
cylinder hydraulic tubes.
MY3930
13
15
16
14
12
MAL1290
17
19
18
17
20
20
20
NOTICE
Guide the push beam extend/retract cylinder
assembly over the top of the retract chain anchor at
the rear of the third boom section being careful not to
damage any components.
NOTICE
Guide the push beam extend/retract cylinder
assembly over the top of the retract chain anchor at
the rear of the third boom section being careful not to
damage any components.