JLG 150HAX ANSI Service Manual - Manual (Page 74)

SECTION 3 - CHASSIS & TURNTABLE
3-36 – JLG Lift – 3120679
3.11 SWING MOTOR
Disassembly
NOTE: Prior to any motor disassembly, plug open ports and
clean all dirt from outside of motor.
1. Mount motor in a vise or other holding device with
shaft facing down.
2. Remove eight bolts (10) from cover/bearing assem-
bly (13).
3. Remove cover/bearing assembly and o-ring (8). Dis-
card o-ring.
4. Remove IGR assembly (6), starting with outer locat-
ing ring and rollers.
NOTE: The innermost IGR component and rotary valve (4)
are retained on shaft by snap ring (7). Do not remove
this snap ring.
5. Remove two check valve balls (5). Check balls fre-
quently fall into body tapped holes or into body
valve ports during disassembly. Ensure check balls
are removed and accounted for.
6. Remove shaft (11), IGR element, and rotary valve as
one assembly.
7. With shaft assembly removed from body, inspect
IGR inner component, rotary valve and shaft for
wear or other damage. Shaft should have a smooth
polished surface in bearing and seal areas. If any of
these components are damaged, snap ring must be
removed and appropriate component replaced. If
snap ring is removed, discard it and install new snap
ring.
8. Quad ring seal (3) and back-up ring (2) can be
removed using a dull pointed object such as a pen-
cil point or the end of a paper clip. DO NOT use a
sharp object such as a knife because the sealing
surface in the body can be damaged.
Assembly
NOTE: Prior to motor assembly, lightly oil all seals, rollers
and threaded bolt ends.
1. Install new back-up ring (2) first, pushing it sealing
surface toward outside of motor. Back-up can be
seated with a dull object.
2. Install new quad ring (3) by pushing it against
inboard side of back-up ring.
3. Lubricate inside diameter of quad ring and back-up
ring with oil or Vaseline.
4. Check output shaft (11) end for burrs and scratches.
Deburr if necessary. Shaft must be free of burrs to
avoid cutting quad ring and back-up ring during
shaft installation.
5. Install shaft assembly into body/bearing assembly
(12).
6. Place contour member of IGR (6) over inner member
and insert seven rollers into inner pockets. (The
seven rollers are larger in diameter than the eight
rollers.)
7. Lightly oil square ring seal (8) and place in body
groove.
8. Place check balls (5) over two 1/8 inch (3.2 mm)
diameter holes in body. Ensure check balls do not
fall into tapped holes in body.
9. Place locating ring section (4.5 inch [11.4 cm] diam-
eter) of IGR onto body with check ball holes facing
downward over balls. Align eight bolt holes in locat-
ing ring with eight holes in body. Holes will align in
only one position. Be sure not to dislodge square
ring seal while moving locating ring.
10. Install eight locating ring rollers into their pockets
and oil lightly.
11. Place lightly oiled square ring seal (8) into groove in
cover and place cover shaft and align bolt holes.
12. Install eight bolts (10) with lightly oiled thread ends
into bolt holes. Tighten diagonally to 15 ft. lb. (20
Nm). Turn shaft by hand through several rotations.
Increase torque of each bolt by 5 ft. lb. (7 Nm) in a
diagonal pattern. Turn shaft by hand through several
rotations. Repeat this procedure until torque of each
bolt has reached 27 ft. lb. (37 Nm).