JLG 120-SXJ ANSI Service Manual User Manual
Page 42
SECTION 3 - CHASSIS & TURNTABLE
3-14
– JLG Lift –
3121105
3.
Remove piston (7) from end cover (2).
4.
Remove o-ring (5), back-up ring (6), o-ring (8) and
back-up ring (9) from piston (7).
5.
Remove separators (13) from housing (21).
6.
Remove stack assembly, consisting of discs (11),
return plate (14) and friction discs (12) from housing
(21).
NOTE: Not all models use the same number of springs or
spring pattern. Record this information for assembly
purposes. Spring retainer (17) was not used in ear-
lier models.
7.
Remove dowel pins (20), springs (15 & 16) and
spring retainer (17) from housing (21).
8.
Remove retaining ring (18) from housing (21).
9.
Remove shaft by pressing or using a soft mallet on
male end of shaft (10).
NOTE: Earlier models did not use retaining ring (22).
10.
Remove retaining ring (22) and bearing (19) from
shaft (10).
11.
Press Rotary oil seal (23) from housing (21).
Cleaning and Inspection
1.
Clean all parts thoroughly.
2.
Closely inspect all parts for excessive wear, cracks,
and chips. Replace parts as necessary.
3.
Discard seals and o-rings.
4.
Closely inspect bearings and bearing contact sur-
faces. Replace as necessary.
NOTE: Bearings may be reused if, after thorough inspection,
they are found to be in good condition.
Assembly
NOTE: Lubricate all seals and o-rings with clean hydraulic
oil prior to assembly.
1.
Clean all parts thoroughly before assembly.
2.
Press new rotary oil seal (23) into housing (21). Note
direction of the seal.
NOTE: Earlier models did not use retaining ring (22).
3.
Install new bearing (19) and retaining ring (22) on
shaft (10).
4.
Insert shaft assembly and retaining ring (18) in hous-
ing (21).
NOTE: Be sure to use the same number of springs and
spring pattern as recorded during disassembly.
Spring retainer (17) was not used in earlier models.
5.
Insert dowel pins (20), spring retainer (17) and
springs (15 & 16) in housing (21).
6.
Position new large diameter return plate (14) in
housing with tabs guided by dowel pins (20) until
disc rests on springs (15 & 16).
DISCS (11, 14) AND FRICTION DISCS (12) SHOULD REMAIN DRY
DURING INSTALLATION. NO OIL RESIDUE SHOULD BE ALLOWED
TO CONTAMINATE DISC SURFACES.
7.
Place a new friction disc (12) on shaft (10) until it
contacts return plate (14).
8.
Add additional new discs (11) and new friction discs
(12) as required to complete assembly.
9.
Insert separators (13) in holes of return plate.
10.
Install new o-ring (5), new backup ring (6), new o-
ring (8) and new back-up ring (9) on piston (7). Note
order of o-rings and back-up rings. Insert piston (7)
into end cover (2) being careful not to shear o-rings
or back-up rings.
11.
Install new case seal (4) in housing (21) then install
bleeder screw (3) in end cover (2).
12.
Position end cover (2) on housing (21) aligning
dowel pins (20) with holes in end cover.
NOTE: If available, a hydraulic press will simplify installation
of end cover on housing. Clamp cover in position
while tightening capscrews.
13.
Press on inner ring of bearing (37) until it shoulders
on shaft (45) to eliminate binding on bearings. Be
certain to restrain opposite end of shaft to avoid
excessive thrust loading on bearing (54).
IF HYDROSTATIC BENCH TESTING IS PERFORMED ON THE
BRAKE ASSEMBLY, RELEASE PRESSURE SHOULD NOT EXCEED
138 BAR UNLESS TWO ADDITIONAL BOLTS ARE USED FOR SUP-
PLEMENTAL CLAMPING.