JLG G6-23A Service Manual - Manual (Page 27)

3.5 G5-19A, G6-23A
Boom
6. Pull the second boom section out 6 in to 8 in
(15 cm to 20 cm) to be able to loosen and remove all
the bolts and remove all the wear pads, backing
plates and shims from the front inside of the first
section boom. Tag each pad, backing plate, shim
and bolts from each location.
7. Remove the clip and pin from the rod end of the
extend/retract cylinder and pull through the rear of
the second boom section.
8. Pull out the remainder of the second boom section.
9. Inspect the boom and welds. Consult your local JLG
distributor if structural damage is detected.
10. Inspect hoses, hardware, wear pads, mounting
points and other components visible with the first
boom section. Replace any item if damaged.
11. Inspect all wear pads for wear. (Refer to Section
3.4.1, “Wear Pad Inspection.”)
3.3.3 Second Section Boom Installation
1. Insert the extend/retract cylinder through the rear of
the second boom section and attach the pin and clip
to the rod end.
2. Install the bottom rear wear pads, washers and bolts
into the first boom section. Apply Loctite ® #242 and
torque to 66 lb-ft (90 Nm). Install the bottom rear left
and right side wear pads, backing plate and bolts (do
not shim or tighten bolts). Install top rear wear pads,
backing plates and bolts (front bolts are drilled and
tapped for zerk fittings, do not shim or tighten bolts).
3. Grease the inside of the first boom section on areas
where the second boom section wear pads will slide.
4. Using a suitable sling, carefully slide the second
boom section 3 ft to 4 ft (1 m to 1.5 m) into the front
of the first boom section. Set the second boom
section head onto suitable supports and reset sling
under the boom head of the second section.
Carefully slide the second section into the first
section. Leave 6 in to 8 in (15 cm to 20 cm) of the
second section out to be able to install wear pads in
front of the first boom section.
5. With the sling still under the boom head, install the
top wear pads, washers and bolts in the front of the
first boom section. Apply Loctite ® #242 and torque
to 66 lb-ft (90 Nm). Lower the second boom section
and install the bottom wear pads, backing plates,
shims and bolts in the front of the first boom section.
Apply Loctite
® #242 and torque to 66 lb-ft (90 Nm).
Install both left and right side front wear pads,
backing plates, shims and bolts in the front of the
first boom section. Apply Loctite
® #242 and torque to
66 lb-ft (90 Nm).
IMPORTANT: Light lubrication of the boom wear
surfaces with a factory authorized grease is
recommended to keep the boom wear surfaces
lubricated properly.
6. Tighten all rear wear pad bolts after ensuring the
minimum gap requirements have been met. Refer to
Section 3.4.1, “Wear Pad Inspection.”
7. Insert the pin and clip into the barrel end of the
extend/retract cylinder.
8. Lift the tilt cylinder into place and insert the pins and
clips to secure the cylinder to the boomhead.
9. Slide the tilt and auxiliary hoses between the boom
sections.
10. Uncap and reconnect the tilt and auxiliary hoses and
attach to their appropriate locations.
3.3.4 Boom Installation
IMPORTANT: Light lubrication of the boom wear
surfaces with a factory authorized grease is
recommended to keep the boom wear surfaces
lubricated properly. Light lubrication of the boom wear
surfaces is also recommended when the machine is
stored, to help prevent rusting.
1. Park the machine on a hard, level surface, place the
transmission control lever in (N) NEUTRAL, engage
the park brake and shut the engine OFF.
2. Place an Do Not Operate Tag on both the ignition
key switch and the steering wheel, stating that the
machine should not be operated.
3. Open the engine cover. Allow the system fluids to
cool.
4. Using suitable slings, turn boom back over to original
orientation.
Note: Grease the boom pivot bore, compensating
cylinder rod ends, lift/lower cylinder rod end and pins
before installing.
5. Using suitable slings, balance the boom assembly,
lift and carefully guide the boom into place. Align the
frame pivot bore with the boom assembly pivot bore.
WARNING:
NEVER weld or drill the
boom unless approved in writing by JLG. The
structural integrity of the boom will be impaired
if subjected to any repair involving welding or
drilling. Failure to comply can result in death or
severe personal injury.