JLG sky trak mmv Service Manual page 174

Boom
3. Remove the retract chain clevis elastic locknut (1) and
washer at the front of the outer boom (2).
2
4. Attach a string, wire or small-diameter rod to the
retract chain clevis. The string, wire or rod must be
long enough to pull the clevis and chain through the
outer boom. This will be used to pull the new chain
through the boom during installation.
5. Remove the complete retract chain and clevis as an
assembly from the rear of the boom.
6. Inspect wear and condition of the booms, chains,
clevis', chain sheaves, extend/retract cylinder, chain
rods, clevis anchors and all mounting hardware.
Replace any worn or damaged parts. DO NOT
attempt to make any repairs to the chain.
IMPORTANT: Chains and clevis' are wear items and
experience the same stress. DO NOT attempt to service or
repair a chain or clevis. Always replace a stretched or
damaged chain or clevis with a new chain assembly,
which includes the chain and both clevis ends.
4.30
Retract Chain Installation
1. Assemble the retract chain and anchor hardware.
2. At the rear of the intermediate boom (3), attach the
retract chain front clevis (4) to the string, wire or
small-diameter rod used in Step 4 of the removal
procedure.
1
3. From the front of the outer boom (5), pull the wire or
rod, retract chain clevis (4) and retract chain
underneath the retract chain sheave (6). Work the
wire or rod forward to the front of the outer boom.
OT04902
Note: ALWAYS use new elastic locknuts to help ensure
proper fastening.
4. Insert the retract chain clevis (4) into its mounting
hole at the bottom front of the outer boom (5).
Secure the clevis with a 3/4" narrow flat washer (7)
and a new 3/4-16 elastic locknut (8) but DO NOT
tighten at this time.
8
Note: ALWAYS use new elastic locknuts to help ensure
proper fastening.
5. At the rear of the inner boom, position the retract chain
anchor links on the mounting tab. Coat a 3/8-16 x 1/2"
x 1-1/2" socket-head shoulder bolt (9) with anti-seize
compound, and install the shoulder bolt in the same
hole as previously noted in the removal procedure.
Secure the links with the shoulder bolt and a new
3/8-16 elastic locknut. Torque nut to 31 lb/ft (42 Nm).
3
5
7
6
4
MM4100
Model MMV Rev. 12/04