JLG G6-42A Service Manual - Manual (Page 61)

3-23 G6-42A, G9-43A, G10-43A
Boom
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.
7. At the back of the boom, verify dimension “C”
3.069 in (77,9 mm) on the extend chain clevis.
Note: Belleville washers are shown in the
un-compressed state.
8. Boom adjustment will be required if the above
dimensions are not met.
3.8.4 Chain Tension Adjustment—
G9-43A/G10-43A
1. Remove extend chain lock nut (1) and loosen
adjustment nut (2) until belleville washers (3) are
free to turn on extend rod.
2. Verify the belleville washers (3) are in the correct
order as shown. Remove the extend chain
adjustment nut (2) and correct if required.
A
MAL2740
MAL2621
B
C
MAL2630
C
MAL2580
3
1
2