JLG 450A_AJ Series II Service Manual - Manual (Page 115)

SECTION 3 - CHASSIS & TURNTABLE
3121180 – JLG Lift – 3-65
Oscillating Axle Lockout Test
LOCKOUT SYSTEM TEST MUST BE PERFORMED QUARTERLY,
ANY TIME A SYSTEM COMPONENT IS REPLACED, OR WHEN
IMPROPER SYSTEM OPERATION IS SUSPECTED.
NOTE: Ensure boom is fully retracted, lowered, and cen-
tered between drive wheels before starting lockout
cylinder test.
1. Place a 6" (15 cm) high block with ascension ramp
in front of left front wheel.
2. From platform control station, activate machine
hydraulic system.
3. Place FUNCTION SPEED CONTROL and DRIVE
SPEED/TORQUE SELECT control switches to LOW
positions.
4. Place DRIVE control lever to FORWARD position
and carefully drive machine up ascension ramp until
left front wheel is on top of block.
5. Carefully activate SWING control lever and position
boom over right side of machine.
6. With boom over right side of machine, place DRIVE
control lever to REVERSE and drive machine off of
block and ramp.
7. Have an assistant check to see left front wheel
remains locked in position off of ground.
8. Carefully activate SWING control lever and return
boom to stowed position (centered between drive
wheels). When boom reaches center, stowed posi-
tion, lockout cylinders should release and allow
wheel to rest on ground, it may be necessary acti-
vate DRIVE to release cylinders.
9. Place 6" (15 cm) high block with ascension ramp in
front of right front wheel.
10. Place DRIVE control lever to FORWARD and care-
fully drive machine up ascension ramp until right
front wheel is on top of block.
11. Carefully activate SWING control lever and position
boom over left side of machine.
12. With boom over left side of machine, place DRIVE
control lever to REVERSE and drive machine off of
block and ramp.
13. Have an assistant check to see that right front wheel
remains locked in position off ground.
14. Carefully activate SWING control lever and return
boom to stowed position (centered between drive
wheels). When boom reaches center, stowed posi-
tion, lockout cylinders should release and allow
wheel to rest on ground, it may be necessary acti-
vate DRIVE to release cylinders.
15. If lockout cylinders do not function properly, have
qualified personnel correct the malfunction before
any further operation.
3.9 SWING BEARING
Description
The swing bearing has five major components: housing,
worm, worm gear, output pinion, and gear/pinion cap.
Servicing of these units requires a press, a 3/8" 12 point
socket, a 1/2" socket, a 3/4" socket, torque wrench (80 ft-
lb), steel hammer, soft face hammer, bearing puller (exter-
nal and internal), and a large flat blade screw driver. Also
needed are a shim and seal kit (refer to JLG Parts Man-
ual), 3/4" steel rod at least 10" long, silicone sealant, Mobil
SHC 007 grease, Mobil SHC 460 grease, Loctite #242 for
bolts, and other parts that may be worn out.
Removal
Refer to Figure 3-48., Swing Bearing Installation.
1. Attach an adequate support sling to boom and draw
all slack from sling. Prop or block boom if possible.
2. Tag and disconnect hydraulic lines (1) running
through center of turntable (2) and frame (3). Use a
suitable container catch residual hydraulic fluid. Cap
lines and ports.
1. Clean area around swing motor (4) to prevent any
dirt from entering system.
2. Tag and disconnect hydraulic lines running to swing
motor. Cap or plug all openings.
3. Attach suitable overhead lifting equipment to base of
turntable weldment (2).
4. Scribe a line on inner race of swing bearing (5) and
underside of turntable to help align bearing during
installation. Remove bolts (6) and washers (7) from
turntable and bearing inner race. Discard bolts.
5. Use lifting equipment to lift complete turntable
assembly from bearing. Ensure no damage occurs
to turntable, bearing, or frame components. Care-
fully place turntable on a suitably supported trestle.
6. Scribe a line on outer race of swing bearing and
frame to help align bearing during installation.
7. Remove bolts (8) and washers (9) from outer race of
bearing to frame. Discard bolts.
8. Use suitable lifting equipment to remove bearing
and rotation box assembly from frame. Move to a
clean, suitably supported work area.