Service Manual

3.137
Model 8042, 10042, 10054 Legacy Rev. 03/04
Boom
3.7.5 Inner Boom Chain Tension
Adjustment
Note: Always perform the Section 3.7.3, “Boom Chain
Tension Check,” before adjusting the inner boom extend
chain tension.
1. Adjust the inner boom extend chain (9):
If the chain sag measurement (10) is less than
1.5" (38 mm), tighten the extend chain adjustment
locknut (11).
If the chain sag measurement (10) is more than
2.5" (64 mm), loosen the extend chain adjustment
locknut (11).
2. If there is no adjustment left on the extend chains,
tighten the retract chain locknut (12) on the bottom of
the primary intermediate boom several turns.
3. Recheck chain tension. (Refer to Section 3.7.3,
“Boom Chain Tension Check.”)
Note: ALWAYS replace elastic locknuts with new elastic
locknuts to help ensure proper fastening.
4. Further chain adjustment can be achieved by
loosening both chain locknuts (11 and 12) and
moving the rear retract chain clevis (1) from the
original mounting hole (2) in the anchor plate to the
next hole (3).
This is only acceptable when boom chain sag (10)
cannot be acquired and the chain elongation
measurement is still less than 12.36" (313 mm).
Make sure to use a new 3/8-16 elastic locknut (4) to
re-secure the chain clevis to the anchor plate. Follow
the instructions in Section 3.7.5, a. “Component/
Assembly Verification.”
OH0551
9
OA0492
10
MH1780
11
OH0660
12