Elevation System Servicing; Lift Chain Length Adjustment; Chain Assembly; General - Big Joe J1-192 Maintenance Repair Parts Manual

7-1. GENERAL.

The elevation system includes the outer mast, inner
mast, lift linkage, drag chains, lift chains, lift cylinder
and ram head.

7-2. LIFT CHAIN LENGTH ADJUSTMENT.

1. Fully lower the Platform.
2. Engage the emergency power disconnect switch
and turn off key switch.
WARNING: Before attempting any adjustment, make
certain power is disconnected.
3. Loosen jam nut to allow for adjustment of middle
jam nut.
4. Break the lower jam nut free from the middle jam
nut.
5. Take up slack in the lift chain with middle jam nut.
6. Align anchor so the clevis pin is parallel to the
mast.
CAUTION: At least 3 full threads must be present
below lower nut after adjustment.
7. Tighten jam nuts securely while maintaining align-
ment of clevis pin.
8. Disengage the emergency power disconnect
switch and turn on key switch.
9. Test chain by operating Platform. If slack is still
apparent, repeat above procedure.
BL-J1-192-0315 - 11-19-2019
SECTION 7

ELEVATION SYSTEM SERVICING

R8171
Figure 7-1 Chain Assembly
7-1