JLG 450A_AJ Series II Service Manual - Manual (Page 66)

SECTION 3 - CHASSIS & TURNTABLE
3-26 – JLG Lift – 3121290
23. Turn housing over and remove swashplate (39) by lifting
on end opposite servo lever.
24. Remove servo piston (40). Remove piston seal (41) and
O-ring (42) from servo piston. Discard seal and O-ring.
25. Remove journal bearings (43) from housing. If bearings
will be reused, note location and orientation of each
bearing for reassembly.
26. Remove pistons (44) and slipper retainer (45) from cylin-
der block (46).
NOTE: Pistons are not selectively fitted. Units with high hourly
usage may develop wear patterns. Number pistons and
bores for reassembly if they will be reused.
27. Remove ball guide (47), hold-down pins (48), and retain-
ing ring (49) from cylinder block.
NOTE: Most repairs do not require block spring removal. Perform
this procedure only if you suspect problems with the block
spring.
RISK OF PERSONAL INJURY: COMPRESSING BLOCK SPRING REQUIRES FORCE
OF ABOUT 80 TO 90 LBF (350 TO 400 N). USE A PRESS SUFFICIENT TO MAIN-
TAIN THIS FORCE WITH REASONABLE EFFORT. ENSURE SPRING IS SECURE
BEFORE ATTEMPTING TO REMOVE SPIRAL RETAINING RING. RELEASE PRES-
SURE SLOWLY AFTER RETAINING RING IS REMOVED.
28. Turn block over. Using a press, apply pressure on block
spring washer (50) to compress block spring enough to
safely remove spiral retaining ring (51). Maintain pres-
sure and unwind spiral retaining ring (51). Carefully
release pressure and remove outer block spring washer
(50), block spring (52), and inner block spring washer
(53) from cylinder block.
41
42
40
Lift here
39
43
38. Swashplate
39. Servo Piston
40. Piston Seal
41. O-ring
42. Journal Bearings
Figure 3-16. Swash Plate & Servo Piston
51
50
52
53
46
49
48
47
45
44
43. Piston
44. Slipper Retainer
45. Cylinder Block
46. Ball Guide
47. Holddown Pins 48. Retaining Ring
49. Block Spring Washer
50. Spiral Retaining Ring
51. Block Spring
52. Inner Block Spring Washer
Figure 3-17. Cylinder Kit Disassembly