JLG 660AJ Service Manual - Manual (Page 67)

SECTION 3 - CHASSIS & TURNTABLE
3121616 – JLG Lift – 3-23
CYLINDER BLOCK
Measure cylinder block height. Replace blocks worn beyond minimum height specification. Inspect cylinder block running surface.
Replace or resurface worn or scratched blocks. Blocks may be resurfaced to specifications shown in the drawing, provided resurfacing
will not reduce block height below minimum specification. Table 3-7, Cylinder Block Measurements.
BALL GUIDE AND SLIPPER RETAINER
Inspect ball guide and slipper retainer for damage, discolor-
ation, or excessive wear. A discolored ball guide or slipper
retainer indicates excessive heat. Do not reuse.
VALVE PLATE
Condition of the valve plate is critical to efficiency of the
motor. Inspect valve plate surfaces carefully 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 plates
may be resurfaced to specifications shown in the drawing,
provided resurfacing will not reduce thickness below mini-
mum specification.
SWASHPLATE AND JOURNAL BEARINGS
Inspect running face, servo ball-joint, and swashplate journal
surfaces for damage or excessive wear. Some material transfer
may appear on these surfaces and is acceptable if surface con-
dition meets specifications shown. Measure swashplate thick-
ness from journals running face. Replace swashplate if
damaged or worn beyond minimum specification. Replace
swashplate if difference in thickness from one side to the other
exceeds specification.
Inspect journal bearings for damage or excessive wear.
Replace journal bearings if scratched, warped, or excessively
worn. The polymer wear layer must be smooth and intact.
A
Table 3-7. Cylinder Block Measurements
Measurement L25 L30 L35 K38 K45
Minimum Cylinder Block Height (A) 50.8 (2.00) 50.8 (2.00) 50.8 (2.00) 54.4 (2.14) 54.4 (2.14)
Cylinder Block Surface Flatness 0.002
(0.0000079)
0.002
(0.0000079)
0.002
(0.0000079)
0.002
(0.0000079)
0.002
(0.0000079)
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]