JLG 450A_AJ Series II Service Manual - Manual (Page 94)

SECTION 3 - CHASSIS & TURNTABLE
3-44 – JLG Lift – 3121180
Inspection
1. Wash all parts thoroughly in a suitable solvent.
2. Examine needle bearings (8) and (20) in housing (9)
and back plate (22 or 27). If needles are free of
excessive play and remain in bearing cage, there is
no need to replace the bearing.
3. Inspect thrust washer (5) and thrust bearing (6). Sur-
faces should be free of any signs of wear or fretting.
4. Inspect spider (12) and pivot (13). Conical surfaces
should be free of wear and score marks.
5. Inspect piston (11). O.D. surface should be smooth
and free of scoring. Shoes should fit snug to piston.
Face of shoes should be flat and free of scoring and
flaking. Do not lap piston shoes.
6. Inspect piston block (14). Bore should be free of
scoring. Surfaces that contact back plate should be
smooth and free of grooves or metal build up. Do
not lap piston block.
7. Inspect thrust race (10). Surface should show no
signs of scoring or grooves.
8. Inspect flat surface on back plate (22 or 27). It
should be free of excessive scoring or metal build
up. Do not lap back plate.
9. Inspect drive shaft (7 or 25) for fretting in bearing
areas. Check spline area for twisted or broken teeth.
If keyed shaft, check for cracked or chipped keyway.