JLG G6-42A Service Manual - Manual (Page 44)

Boom
3-6 G6-42A, G9-43A, G10-43A
15. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
16. Install the previously removed attachment to the
quick coupler assembly. Refer to Section 3.15,
“Troubleshooting.”
3.5 BOOM SECTION REMOVAL/
INSTALLATION
3.5.1 Second and Third Boom Section
Removal
Note: Refer to Section 3.14.2, 3.16. “Push Beam
Temporary Brackets,” for diagrams of the Temporary
Extend Bracket and Temporary Retract Bracket
designed to hold the chains in place on the push beam
during disassembly and reassembly.
These brackets are NOT a purchasable part and must be
manufactured locally.
They are solely designed to aid in the removal and
installation of the push beam assembly.
Note: Refer to Section 8.8, “Hydraulic Cylinders.” for
general tilt cylinder removal.
1. Remove the access cover from the rear of the first
boom section.
2. Remove the locknut, adjustment nut and six
belleville washers (1) from the extend chain clevis
rod at the rear of the boom.
3. Loosen and remove both extend/retract cylinder
tubes (2) from the rear of the boom. Cap and/or plug
all open hoses, tubes and/or fittings to prevent dirt
and debris from entering the hydraulic system.
4. Slowly loosen and remove the extend/retract
cylinder counterbalance valve (3). Plug (M27x1.5)
the open port on the extend/retract cylinder to
prevent dirt and debris from entering the hydraulic
system.
5. Remove the retaining clips from the extend/retract
cylinder mounting pin (4), remove the extend/retract
cylinder pin.
6. Remove the four mounting bolts securing the strong
back (5) to the first boom section.
7. Remove the strong back (5) from the rear of the
boom.
8. Remove the right or left side wear pads, shims and
backing plates (6) from the rear of the second boom
section. Label and tag each set of wear pads being
removed.
9. Remove the top wear pads, shims and backing
plates (7) from the rear of the second boom section.
Label and tag each set of wear pads being removed.
10. Loosen and remove the four bolts (8) securing the
retract chain anchor plate (9).
11. Between the bottom front of the first and second
boom sections, feed a rope or wire to the retract
chain anchor plate and secure to the second or third
boom section.
12. Disconnect both tilt tubes (10) and (if equipped) both
auxiliary tubes from the fittings on the hose retainer
brackets (11) at the bottom front inside the boom.
Plug the tube ends to prevent dirt and debris from
entering the hydraulic system.
13. Disconnect both tilt hoses (not shown) and (if
equipped) both auxiliary hoses from the hose
retainer brackets at the bottom front inside the boom.
Plug the hose ends to prevent dirt and debris from
entering the hydraulic system.
14. Loosen and remove the hose retainer brackets (11)
and (if equipped) both auxiliary take-up brackets.
MAL2660
1
2 2
4
5
6
3
6
7 7
G6-42A
G9-43A
G10-43A
MY3860
10
11
9
8
8