JLG 18RS Service Manual - Manual (Page 72)

SECTION 3 - CHASSIS & TURNTABLE
3-34 – JLG Lift – 3121284
Disassembly
Refer to Figure 3-10., Swing Bearing Drive.
1. Clean area around swing motor (1) to prevent any dirt
from entering system.
2. Tag and disconnect hydraulic lines running to swing
motor. Cap or plug all openings.
SECURE WORM GEAR SHAFT SO IT DOES NOT PULL OUT ANY WHEN REMOVING
THE SWING MOTOR. FAILURE TO DO SO COULD DAMAGE WORM GEAR SEALS.
3. Remove bolts (2) and washers (3) securing swing motor
to swing drive housing (4).
4. Carefully pull swing motor from housing.
Refer to Figure 3-7., Swing Motor Removal and Installation.
1. Remove two 5/16" bolts (5) and washers (6) that hold
turntable bearing (7) to housing (4).
2. Remove two #6 machine screws (8) on cover plate (9)
immediately in front of pinion (10).
3. Remove eight 3/8" 12 point cap screws (11) from gear
pinion cap (12). Pry cap from housing. Cover plate (9)
will come off with cap. Note where sealant is on cover
and plate so it can be applied in same location during
assembly. Note number and color of shims (14) between
cap and housing.
4. Remove six small screws (15) from cover plate. Pry cover
plate (9) from cap (12). Discard cover plate. Note number
and color of shims (13) between cover plate and cap.
NOTE: If there are five screws or drive screws holding cover plate
to cap, a new cap (12) should be ordered. This is an older
version; new cover plate has six holes.
5. Lift directly up and remove pinon and gear assembly
(10, 16, 17, 34, 18 - 22) from housing (4).
6. Disassemble pinion and gear assembly using a press.
Support worm gear (20) on press wIth pinion (10) facing
down, allowing room for pinion to be pressed out of
gear. Press pinon out of bearing (22), spacer (21), and
worm gear (20).
7. Remove face seal (18) and O-ring (19) from face of worm
gear (20). Note how seal is assembled.
8. Remove bearing (17) and Nilos Ring (16) from pinion (18)
with an external bearing puller or press.
9. Remove motor adapter (33) and shim (34).
10. Remove two 1/2" bolts (25) from worm cap (26) with a 3/
4" socket. Remove shIms (27) and seal (28) and discard.
11. Remove worm (29) from housing (4) by pushing worm
from motor end using a steel rod and hammer. Use a
soft hammer to tap worm on hex end to remove bearing
(36) from opposite end of housing.
12. Remove bearing (30) from worm (29) using an external
bearing puller or press.
13. Remove press fit bearing cup (35) from adapter (33)
using a small pry bar or by welding a small bead of weld
on internal diameter of the cup.
Assembly
Refer to Figure 3-10., Swing Bearing Drive.
1. Press bearing cup (17) in cap (12).
2. Place bearing cup (33) in housing (4).
3. Put face seal (18) and O-ring (19) on hub of worm gear
(20).
4. Place worm gear (20) on press with face seal up and
press pinion (10) into worm gear. Place Nilos Ring (16)
on pinion so cup shape is up and press bearing (34) on
pinion tight to Nilos Ring.
5. Turn assembly over and place spacer (21) on pinion
against gear hub so hub of spacer faces up. Press bear-
ing (22) on pinion and tight to spacer and gear.
6. Place pinion gear assembly in housing. Place gear cap
(12) and shims (14) over gear/pinion assembly to
achieve a slight preload on pinion bearings. Remove cap
and shims and set shims aside. Install a new cover plate
(9) on cap with six screws (15) and shims (13) equal or
close to total thickness of shims removed. Apply sealant
(Permatex #2) to both sides of each shim and tighten
screws, taking care not to twist screws off. Set assembly
aside.
ROLLER BEARINGS (30,36) AND CUPS (32,35) MUST BE INSTALLED WITH
SMALL ENDS FACING OUT ON EACH SIDE OF MACHINE OR EXCESSIVE PLAY
WILL CAUSE BINDING AND DAMAGE TO EQUIPMENT.
7. Install bearing (36) with small end facing to outside of
machine on bore end of worm (34).