JLG 660AJ Service Manual - Manual (Page 89)

SECTION 3 - CHASSIS & TURNTABLE
3121616 – JLG Lift – 3-45
3.9 SWING BRAKE - MICO
Disassembly
1. With shaft protrusion downward, remove end cover (13)
by removing capscrews (12).
END COVER IS UNDER SPRING TENSION OF APPROXIMATELY 2000 POUNDS
(681 KG). THE FOUR CAPSCREWS SHOULD BE LOOSENED EVENLY TO RELIEVE
THIS FORCE. IF A HYDRAULIC PRESS IS AVAILABLE (3000 LBS (1362 KG) MAX-
IMUM), COVER CAN BE HELD IN POSITION WHILE REMOVING CAPSCREWS AND
LOCKWASHERS.
2. Remove case seal (11) from housing (7) then remove
bleeder screw (14) from end cover (52).
3. Remove piston (22) from end cover (13).
4. Remove O-ring (17), back-up ring (16), O-ring (19) and
back-up ring (18) from piston (22).
5. Remove separators (10) from housing (52).
6. Remove stack assembly consisting of discs (21), return
plate (8), and friction discs (20) from housing (52).
7. Remove dowel pins (15), springs (5 & 6) from housing
(52).
8. Remove retaining ring (3) from housing (52).
9. Remove shaft by pressing or using a soft mallet on male
end of shaft (51).
10. Remove retaining ring (54) bearing (2) from shaft (51).
11. Press rotary seal (1) from housing (51).
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 surfaces.
Replace as necessary.
NOTE: Bearings may be reused after thorough inspection if they
are in good condition.
Assembly
NOTE: Lubricate all seals and O-rings with clean hydraulic oil prior
to assembly.
1. Press new rotary seal (1) into housing (52). Note direc-
tion of seal.
2. Install new bearing (2) on shaft (51).
3. Install shaft assembly and retaining ring (3) into housing
(52).
4. Install dowel pins (15), spring retainer (55), and springs
(5 & 6) into housing (52).
NOTE: Use same number of springs and spring pattern as
recorded during disassembly.
5. Position new large diameter return plate (8) in housing
with tabs guided by dowel pins (15) until disc rests on
springs (5 & 6).
NOTE: Discs (21 & 8) and friction discs (20) should remain dry dur-
ing installation. Oil will contaminate disc surfaces.
6. Place new disc (20) on shaft (51) until it contacts return
plate (8).
7. Add additional discs (21) as required to complete assem-
bly.
8. Insert separators (10) in holes of return plate (8).
9. Install new O-ring (17), new back-up ring (16), new O-
ring (19) and new back-up ring (18) on piston (22). Insert
piston (22) into end cover (13). Do not shear O-rings or
back-up rings.
10. Install new case seal (11) in housing (52). Install bleeder
screw (14) in end cover.
11. Position end cover (13) on housing (52). Align dowel
pins (15) with holes in end cover.
12. Insert capscrews (12) and tighten evenly to draw end
cover (13) to housing (52). Torque capscrews to 55 ft-lb
(75 Nm).