JLG G6-42A Service Manual - Manual (Page 43)

3-5 G6-42A, G9-43A, G10-43A
Boom
3.4 COMPLETE BOOM REMOVAL/
INSTALLATION
3.4.1 Complete Boom Removal
1. Remove any attachment from the quick coupler
assembly. Refer to Section 3.15, “Troubleshooting.”
2. Remove the quick coupler assembly. Refer to
Section 3.9.1, “Quick Switch Removal.”
3. If equipped, remove the boom head mounted winch.
Refer to Section 3.9.4, 3.10. “Boom Head - Mounted
Winch.”
4. Park the machine on a hard, level surface, level the
machine, fully retract the boom, level the boom,
place the transmission control lever in
(N) NEUTRAL, engage the park brake and shut the
engine OFF.
5. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
6. Open the engine cover. Allow the system fluids to
cool.
7. Properly disconnect the battery.
8. Using a suitable sling or hoist, support the boom.
9. Label, disconnect and cap the hydraulic hoses at the
rear of the boom. Cap all fittings to keep dirt & debris
from entering the hydraulic system.
10. Label and disconnect any electrical cables
(if equipped) at the rear of the boom.
11. Remove the pin from the rod end of the
compensation cylinder being careful not to drop the
cylinder. Lower the cylinder onto the frame rails.
12. Remove the pin from the rod end of the lift/lower
cylinder. Lower the cylinder onto the frame rails.
13. Confirm that the boom assembly is balanced with
the sling and remove the boom assembly
pivot pin (1).
14. Lift the boom assembly from the machine and lower
onto suitable supports.
3.4.2 Complete Boom Installation
1. Park the machine on a hard, level surface, place the
transmission control lever in (N) NEUTRAL, engage
the park brake, chock the wheels and shut the
engine OFF.
2. 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.
Install the boom pivot pin (1).
3. With the sling still in place, install the compensation
cylinder, pins and bolts. Apply Loctite ® 242 TM and
torque lock bolt to 100-110 lb-ft (135-149 Nm).
4. With the sling still in place, install the rod end of the
lift/lower cylinder, pin and lock bolt. Apply Loctite ®
242 TM and torque lock bolt to 200-215 lb-ft
(271-291 Nm).
Note: Raising the boom up or down with the sling my be
necessary so the boom, compensation and lift/lower
cylinder bores can be aligned for easier pin installation.
Note: Grease the boom pivot bore, compensation
cylinder rod end, lift/lower cylinder rod end and pins
before installing.
5. Uncap and reconnect the previously labeled
hydraulic hoses to the extend/retract cylinder.
6. Uncap and connect and remaining hydraulic fittings
to their appropriate locations.
7. Recheck wear pad gaps to ensure they meet the
minimum gap requirement. Shim if necessary.
8. Ensure that the boom chains are properly adjusted.
Refer to Section 3.8, “Boom Adjustments.”
9. If equipped, install the boom head mounted winch.
Refer to Section 3.9.4, 3.10. “Boom Head - Mounted
Winch.”
10. Properly connect the battery.
11. Install the quick coupler assembly. Refer to Section
3.9.2, “Quick Switch Installation.”
12. Start the engine and operate all boom functions
several times. Check for leaks, and check the
hydraulic fluid level in the reservoir; add fluid if
required.
13. Clean up all debris, hydraulic fluid, etc., in, on, near
and around the machine.
14. Close and secure the engine cover.
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