JLG 510AJ Service Manual - Manual (Page 102)

SECTION 3 - CHASSIS AND TURNTABLE
3-60 – JLG Lift – 3121181
3.8 SWING BEARING
Description
The swing bearing has five major components. They are the
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 lb-ft), steel
hammer, soft face hammer, bearing puller (external and inter-
nal), large flat blade screw driver. Also needed are a shIm and
seal kit (refer to the JLG Parts Manual), 3/4" steel rod at least
10" long, silicone sealant, Mobil SHC 007 grease, Mobil SHC
460 grease, Loctite #242 for bolts, and any other parts that
may be worn out.
Removal
1. Attach an adequate support sling to the boom and draw
all slack from sling. Prop or block the boom if feasible.
2. Tag and disconnect hydraulic lines running through
center of turntable and frame. Use a suitable container
to retain any residual hydraulic fluid. Cap lines and ports.
3. Attach suitable overhead lifting equipment to the base
of turntable weldment.
4. Use a suitable tool to scribe a line on the inner race of
the swing bearing and on the underside of the turnta-
ble. This will aid in aligning the bearing upon installa-
tion. Remove bolts, nuts and washers which attach the
turntable to the bearing inner race. Discard nuts and
bolts.
5. Use lifting equipment to carefully lift complete turnta-
ble assembly from the bearing. Ensure no damage
occurs to turntable, bearing, or frame mounted compo-
nents.
6. Carefully place turntable on a suitably supported trestle.
7. Use a suitable tool to scribe a line on the outer race of
the swing bearing and the frame. This line will aid in
aligning the bearing upon installation. Remove the bolts
and washers which attach the outer race of the bearing
to the frame. Discard the bolts. Use suitable lifting
equipment to remove the bearing and rotation box
assembly from the frame; move to a clean, suitably sup-
ported work area.
8. Remove two capscrews securing bearing to the rotation
box to separate for inspection.
Disassembly
1. Remove swing bearing assembly from machine.
2. To remove the large turntable bearing (9), remove two
5/16" bolts (6) and washers (7) that hold the turntable
bearing to the housing (20).
3. Remove the two #6 machine screws (29) that are located
on the cover plate (21) immediately in front of the pin-
ion (18).
4. Remove eight 3/8" 12 point cap screws (3) from gear
pinion cap (27). Pry cap from housing. The cover plate
(21) wIll come off with the cap. Note where sealant is on
the cover and plate so the sealant can be applied in the
same place during assembly. Note number and color of
shims (31, 32, 33 - 35, 36) between cap and housing.
Remove 6 small screws (30) from cover plate. Pry cover
plate (21) from cap (27) and discard cover plate. Note
number and color of shims between cover plate and
cap.
If there are 5 screws or drive screws holding cover plate
to the cap then a new cap (27) should be ordered. This is
an older version, the new cover plate has 6 holes.
5. Remove pinon and gear assembly (18,17,13,
14,38,16,19) from housing (20). It lifts directly upward
from housing.
6. Disassemble pinion and gear assembly using a press.
Support worm gear (17) on press wIth pinion (18) down,
allowing room for pinion to be pressed out of the gear.
Press pinon out of bearing (16), spacer (19), and worm
gear (17) by pressing on the end of pinion.
7. Remove face seal (38) and O-ring (10) from face of the
worm gear (17). Note how seal is assembled.