JLG G6-42A Service Manual - Manual (Page 53)

3-15 G6-42A, G9-43A, G10-43A
Boom
8. Remove the extend chain adjustment nut and lock
nut (6) from the strong back.
9. Remove the retract chain adjustment and lock nuts
(7) from the front of the first boom section.
10. Remove the strong back mounting bolts and remove
the strong back from the boom.
11. Remove the push beam mounting pins from the rear
of the second boom section.
12. Place the chain clevis rod to one side of the push
beam.
13. Lift the push beam to gain access to the chain clevis
at the rear of the third boom section.
14. Reaching inside the rear of the boom at the chain
anchor bracket, remove the cotter pin and pin from
the retract chain clevis. Remove the cotter pin and
pin from the extend chain.
15. Connect wire or rope (approximately 30 ft (9,1 m) to
the end of the extend chain.
16. Lower the push beam. Center the chain clevis rod on
the push beam to aid in removal.
17. Pull the push beam/extend chain from the rear of the
boom. Disconnect the wire or rope from the extend
chain.
18. Pull the retract chain from the rear of the boom.
3.6.2 Extend/Retract 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. Push the retract chain through the boom from the
rear to the chain adjusting block (7) on the first boom
section. Do not tighten the adjustment and lock nut
at this time. Thread the nut on the clevis enough to
keep the chain in place.
2. Connect the extend chain to the wire or rope at the
rear of the boom.
3. Slowly pull the wire or rope guiding the extend chain
over the push beam, around the extend chain
sheave, under the push beam and stopping at the
extend chain/retract chain clevis.
4. Remove the wire or rope secured to the extend
chain.
5. Place the chain clevis rod to one side of the push
beam.
6. Lift the push beam to gain access to the chain clevis
at the rear of the third boom section.
7. Reaching inside the rear of the boom at the chain
anchor bracket, install the cotter pin and pin from the
extend chain clevis. Install the cotter pin and pin from
the retract chain.
8. Lower the push beam. Center the chain clevis rod on
the push beam.
9. Place the extend chain rod through the strong back
and place the strong back in place at the rear of the
first boom section.
10. Install and torque the strong back mounting bolts to
240-265 lb-ft (325-359 Nm).
11. Install the extend/retract cylinder mounting pin and
secure with retaining clips.
12. Install the adjustment and lock nuts on the chain
clevis rod. Do not tighten at this time.
13. Uncap and connect the extend/retract cylinder
hydraulic tubes to their appropriate locations.
14. Adjust the chain as needed. Refer to Section 3.8,
“Boom Adjustments.”
15. Install the cover on the rear of the boom.
16. Properly connect the battery.
17. Close and secure the engine cover.
18. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
MY1540
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