JLG 450A_AJ Series II Service Manual - Manual (Page 105)

SECTION 3 - CHASSIS & TURNTABLE
3121180 – JLG Lift – 3-55
BALL GUIDE AND SLIPPER RETAINER
Inspect ball guide and slipper retainer for damage, discol-
oration, or excessive wear. A discolored ball guide or slip-
per retainer indicates excessive heat. Do not reuse.
VALVE PLATE
Valve plate condition is critical to motor efficiency. Inspect
valve plate surfaces for excessive wear, grooves, or
scratches. Replace or resurface grooved or scratched
valve plates. Measure valve plate thickness and replace if
worn beyond minimum specification. Valve plate can be
resurfaced if finished thickness is not below minimum
specification shown in drawing.
SWASHPLATE AND JOURNAL BEARINGS
Inspect running face, servo ball-joint, and swashplate jour-
nal surfaces for damage or excessive wear. Some material
transfer may appear on these surfaces and is acceptable
providing surface condition meets specifications shown.
Measure swashplate thickness from journals to running
face. Replace swashplate if damaged or worn beyond
minimum specification.
Inspect journal bearings for damage or excessive wear.
Replace journal bearings if scratched, warped, or exces-
sively worn. Polymer wear layer must be smooth and intact.
SHAFT BEARINGS
Inspect bearings for excessive wear or contamination.
Rotate bearings while feeling for uneven movement. Bear-
ings should spin smoothly and freely. Replace bearings
that appear worn or do not rotate smoothly.
Slipper retainer
Ball guide
3.83 mm [0.151 in] min.
0.025 mm
[0.001 in]
0.0076 mm
[0.00030 in]
convex max
LV
25.8 mm
[1.015 in]
24.6 mm
[0.969 in] KV
Thickness equality
side to side:
0.05 mm [0.002 in]
0.0025 mm
[0.0001 in]