JLG 4017PS Service Manual - Manual (Page 70)

Boom
3-32 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
3.15 BOOM SECTIONS ADJUSTMENT
3.15.1 Chain Adjustments
The chains are adjusted by tightening and/or backing off
the adjusting nuts at the threaded end of the chains. The
opposite chain adjusting nut usually must be loosened
whenever this procedure is performed.
Fully retract and level the boom.
The boom is properly adjusted whenever the following
parameters are met.
A. 797 ±3mm (31.0 ±0.12in)
B. 499 ±3mm (19.9 ±0.12in)
C. 229 ±3mm (9.0 ±0.12in)
D. 20mm (0.80in)
1. If adjustments are needed: Start the machine, level
the boom and extend the boom 0,91m to 1,2m
(3 ft to 4 ft). Turn OFF engine.
2. Loosen the locknuts on the extend and retract
chains.
3. Adjust extend chains (1) and retract chains (2) to
ensure a gap of (D) between the face of the second
boom section and the shoulder of the third boom
section. The retract chains (2) are accessible from
the side of the boom.
4. Adjust extend chains (3) and retract chain (4) to
ensure a gap of (C) between the face of the third
boom section and the center of the tilt cylinder pin on
the fourth boom section. The retract chain (4) is
accessible from the rear of the boom.
5. Adjust extend chains (1 & 3) and retract chain(s)
(2 & 4) to ensure a gap of (A & B) for the overall
boom section adjustment.
6. Tighten the extend and retract chain lock nuts to 120
Nm (86 lb-ft) against the adjusting nut.
Note: Ensure that there is a minimum of one full thread
of the clevis showing beyond the lock nut.
7. Start the machine and slowly extend and retract the
boom three times.
8. Retract the extend/retract cylinder completely. Turn
OFF engine.
9. Verify boom section dimensions. Repeat steps 1 thru
7 if necessary.
10. Start the machine, lower the out riggers if necessary
and extend the boom to maximum extension, then
retract 51 to 76 mm (2 to 3 in). Shut machine off.
A
C
B
D MY3660
MY3670
1
3
MY3680
2 2
2
4