JLG G12-55A Service Manual - Manual (Page 48)

Boom
3-12 G10-55A, G12-55A
3.5.7 Third Boom Section Assembly
Note: Inspect and lubricate all extend and retract chains
before re-assembly. Refer to Section 3.11.1, “Boom
Chain Inspection,” for detailed information.
Note: Using a straight bar approximately 40 in
(1041 mm) long will aid in the installation of the wear
pads located on the inside front of each boom section.
1. Place the third boom section onto suitable supports.
2. Install the previously removed chain roller (1) at the
rear of the third boom section. Insert the mounting
pin, retainer plate and hardware. Torque as required.
3. Install all wear pads, spacers and shims (2, 3 and 4)
at rear of third boom section. Snug mounting bolts.
Shim as needed AFTER boom section is
installed.Refer to Section 3.9.2, “Wear Pad
Installation and Lubrication,” for detailed information.
4. Install the previously removed extend chain
assemblies and clevises (5) at the top rear of the
third boom section. Allow 0.250 in (6,35 mm)
between the end of the clevis (5) and the face of the
lock nut (6). Torque lock nut to 100 lb-ft (135 Nm).
3.5.8 Fourth Boom Section Installation
Note: Using a straight bar approximately 40 in
(1041 mm) long will aid in the installation of the wear
pads located on the inside front of each boom section.
1. Clean and lubricate the bottom of the fourth boom
section where the wear pads of the third boom
section contact the fourth boom section.
2. Place sling, or two slings for better stability, around
fourth boom section and slowly insert fourth boom
section into third boom section being careful not to
damage any surrounding components.
3. Install the wear pad, support plates and spacers (7)
with existing hardware at the inside top front of the
third boom section. Snug mounting bolts. Shim as
needed AFTER boom section is installed. Refer to
Section 3.9.2, “Wear Pad Installation and
Lubrication,” for detailed information.
MY3500
2
1
2
3
3
4 4
MY3630
C
6 5
MY3510
7
8
8
7
8 8