JLG G12-55A AccuPlace Service Manual - Manual (Page 35)

3.13 G10-55A & G12-55A AccuPlace
Boom
3.4.6 Retract Chain Installation
Inspect and lubricate chains thoroughly before
installation. Articulate the chains to make sure all working
surfaces are thoroughly lubricated.
Note: If the inner retract chain was removed, it must be
installed first.
1. Fasten a rope to the end of the 3/4 in. chain in order
to pull it back into the boom.
2. Attach the chain to the chain clevis at the rear of the
boom.
3. Carefully pull the chain into the boom until it can be
fastened to the chain clevis.
4. Remove the rope.
5. Fasten the chain into the clevis by installing the pin
and retaining ring.
6. Apply Loctite ® 242 to the jam nut threads and torque
to 100 lb-ft (135 Nm).
To install the outer retract chain:
1. Fasten a rope to the end of the chain in order to pull
it back into the boom.
2. Attach the chain to the chain clevis at the rear of the
boom.
3. Carefully pull the chain into the boom until it can be
fastened to the chain clevis.
4. Remove the rope.
5. Fastened the chain into the clevis by installing the
pin and cotter pin.
6. Install the chain adjustment block and mounting
bolts. Torque the chain adjustment block mounting
bolts to 360-390 lb-ft (475-530 Nm).
7. Install the extend/retract cylinder and cylinder
support.
8. Adjust the retract chains as needed. Refer to Section
3.5, “Boom Section Separation Adjustment.”
9. Connect the battery negative (-) cable to the battery
negative (-) terminal.
3.4.7 Extend Chain Removal
The following section explains the removal of the extend
chains without removing the boom assemblies.
1. Park the machine on level ground. Place the
transmission control lever in (N) NEUTRAL, engage
the parking brake switch, level the boom, extend the
boom far enough to access the chain anchor and the
clevis through the top rear access hole, shut the
engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
3. Remove the battery negative (-) cable from the
battery negative (-) terminal.
4. Secure the boom sections together to prevent
uncontrolled boom run out when the extend chains
are removed.
5. On the chain being removed, loosen and remove the
jam nut from the rear chain clevis and back off the
adjusting nut on the chain clevis to the end of the
threads. Do not completely remove the nut.
6. Remove the chain clevis pin and retaining ring to
free the chain.
7. Install the nylon tie wrap through the holes in the
chain, making a loop with the tie wrap and tie a rope
to the loop.
8. Pull the slack to the chain clevis at the front of the
boom.
9. Remove the clevis pin and the retaining ring from the
chain and chain clevis.
10. Install a nylon tie wrap through the chain holes,
forming a loop and tie a rope to the loop.
11. Carefully pull the chain out of the boom.
12. Untie the rope and leave it in place for reinstallation
of the chain.
3.4.8 Extend Chain Installation
The following section explains the installation of the
retract chains without removing the boom assemblies.
Inspect and lubricate chains thoroughly before
installation.
1. Fasten the previously used rope to the end of the
extend chain.
2. Carefully pull the chain into the boom to the chain
clevis anchor.
3. Fasten the chain to clevis with a pin and cotter pin.
4. At the other end of the chain, connect the chain to
the clevis fastening the chain to the clevis with a pin
and retaining ring.
5. Install the chain clevis fastening and adjusting
hardware on both ends.
6. Remove any clamping devises being used to keep
the boom sections from moving.
7. Adjust the extend chains as needed. Refer to
Section 3.5, “Boom Section Separation Adjustment.”