JLG G12-55A Service Manual - Manual (Page 50)

Boom
3-16 G10-55A, G12-55A
6. Connect the rear retract chain (4) to the chain clevis
with the previously removed pin at the rear of the
third boom section. Secure the pin with the
previously removed snap rings.
7. Pull hose carrier from the rear as far as possible to
access the hydraulic and if equipped, the electrical
connections.
8. If equipped, connect the electrical cable (5) to the
fitting on the hose carrier.
9. Remove any caps and plugs from the tilt and
auxiliary hoses at the rear of the boom assembly.
Connect and tighten the tilt (6) and auxiliary hoses
(7) to their proper fitting locations on the hose
carrier. Torque as required.
10. Install the hose carrier bracket (8) at the rear of the
third boom section and the hose carrier. Torque
mounting bolts as required.
11. Install both hose sheave covers (9).Torque mounting
bolts as required.
12. Connect the fourth boom section extend chain (10)
to the clevis at the top front of the third boom section
and adjust to the previously measured setting. Do
Not tighten the lock nut at this time.
13. Connect the third boom section extend chains (11) to
the clevises at the top front of the second boom
section and adjust to the previously measured
setting. Do Not tighten the lock nut at this time.
14. Grease all wear pad at the rear of the boom using
the zerk fittings.
15. Refer to Section 3.7, “Boom Section Separation
Adjustment,” for proper boom section adjustments.
3.6 EXTEND/RETRACT CHAIN
REMOVAL/INSTALLATION
3.6.1 Retract Chain Removal
The following section explains the removal of the retract
chains without removing the boom assemblies.
Note: The retract chain on the bottom of the boom must
be removed to gain access to the inner retract chain.
To remove the retract chain from the third to first boom
sections:
1. Park the machine on level ground. Place the
transmission control lever in (N) NEUTRAL, engage
the parking brake switch, level the boom and shut
the engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
3. Properly disconnect the battery.
MY3590
4
5
MY3420
6 7
8
9
9
MY3440
10 11