JLG G6-42A Service Manual - Manual (Page 47)

3-9 G6-42A, G9-43A, G10-43A
Boom
3.5.3 Push Beam—Extend/Retract
Cylinder Removal
1. Loosen the Temporary Extend Chain Retention
Bracket (13) and push the push beam (14) forward
3-4 in (76,2-101,6 mm).
2. Attach the Temporary Extend Chain Retention
Bracket (15) between the chain clevis (16) and the
end of the push beam (14).
Note: Refer to Section 3.15, “Push Beam Temporary
Brackets,” for Temporary Extend Chain Bracket diagram.
3. Lift push beam (14) to unload clevis pin (17) and
remove pin securing clevis to third boom section.
4. Tighten the Temporary Extend Chain Retention
Bracket (13) to remove any slack in the extend chain.
5. Secure a rope or wire to front of push beam and pull
push beam (14) towards front of boom.
6. Support push beam assembly with pry bars using
access holes on each side of third boom section.
7. Remove the guide bar (18) and chain retainer (19).
Remove the push beam wear pad (20).
8. Lower push beam assembly and remove pry bars.
9. Push/pull push beam assembly along with extend
chain, to front of third boom section.
10. Place a sling around the push beam assembly. Lift
and slowly pull the push beam assembly
approximately half way out of the third boom section.
Lower the push beam onto a suitable support.
11. Relocate sling or using two slings for better stability,
balance push beam assembly and slowly pull push
beam assembly out the front of third boom section.
12. Lower push beam assembly onto suitable supports.
13. Remove all remaining brackets, clevises, hoses,
wear pads, shims, backing plates and hardware from
the second and third boom sections. Label all parts
and hardware being removed from each section.
Note: Inspect all chains, hoses and sheaves for wear
and/or damage and replace as needed.
3.5.4 Push Beam—Extend/Retract Cylinder
Installation and Third Boom Section
Assembly
Note: Inspect the wear pad surfaces of the second and
third boom sections. Verify all areas are clean and free of
any weld spatter, paint, etc., before beginning the re-
assembly procedure.
Note: Inspect and lubricate all extend and retract chains
before re-assembly. Refer to Section 3.11, “Boom
Extend and Retract Chains,” for detailed information.
1. Place the third boom section onto suitable supports.
2. Clean and lubricate the bottom and sides of third
boom section where push beam guide bar travels.
3. Place a sling or using two slings for better stability,
lift and slowly push the push beam assembly
approximately half way into the third boom section.
Lower the push beam onto a suitable support.
CAUTION
The complete push beam assembly weighs over
1,200 lb (545 kg).
MY4060 13
15 14 16 17
MY3930
18
14
20
19
NOTICE
Guide the push beam/extend/retract cylinder
assembly over the top of the retract chain anchor at
the rear of the third boom section being careful not to
damage any components.