JLG G6-42A Service Manual - Manual (Page 60)

Boom
3-22 G6-42A, G9-43A, G10-43A
9. Tighten the retract chain adjustment nut (6) until
the belleville washers (7) become fully compressed
to dimension “B” 0.712-0.725 in (18,1-18,4 mm). Do
Not Overtighten.
10. Install and temporarily tighten the retract chain
lock nut (4).
11. Start the machine and at low idle, fully extend and
retract the boom three times. Verify boom is fully
retracted and level. Shut machine Off.
12. Recheck the Belleville washers (7) to verify they are
fully compressed to dimension “B” 0.712-0.725 in
(18,1-18,4 mm). If required, re-tighten the retract
chain adjustment nut (6) until dimension “B” is
obtained.
Note: If dimension “B” requires adjustment, continue to
step 13. If dimension “B” does NOT require adjustment,
continue to step 14.
13. Start the machine and at low idle, fully extend and
retract the boom three times. Verify boom is fully
retracted and level. Shut machine Off.
14. Verify dimension “A” 11.500-11.812 in
(292,1- 300,0 mm). Verify dimension “C” is not less
than 2.850 in (72,4 mm).
Note: Re-adjust boom if dimensions “A” & “C” are not
met. Contact the local JLG Distributor if the procedure
cannot be obtained.
15. Loosen the retract chain lock nut and the extend
chain lock nut and apply Loctite ® 242 TM .
16. Torque each retract chain lock nut (4) and
extend chain lock nut (1) without adding any
additional spring load. Torque each lock nut to
100 lb-ft (135 Nm).
3.8.3 Chain Tension Inspection—
G9-43A/G10-43A
1. Park machine on level ground. Place transmission
control lever in (N) NEUTRAL, engage parking brake
and level boom.
2. Place a Do Not Operate Tag on both ignition key
switch and steering wheel.
3. Extend the boom 4-5 ft (1,2-1,5 m), then fully retract
the boom. Verify boom is level.
4. Measure the following three dimensions; A, B & C.
5. At the boom head, verify dimension “A” is between
17.000-17.312 in (421,8-439,7 mm).
6. At the bottom front of the boom, verify dimension “B”
is 1.500-1.512 in (38,1-38,4 mm) of the washer stack
on the retract chain clevis.
B
MAL2551
4
5
6 7
A
MAL2740
MAL2621
B