JLG 510AJ Service Manual - Manual (Page 91)

SECTION 3 - CHASSIS AND TURNTABLE
3121181 – JLG Lift – 3-49
CYLINDER BLOCK
Measure the cylinder block height. Replace blocks worn
beyond the minimum height specification. Inspect the run-
ning surface of the cylinder block. Replace or resurface worn
or scratched blocks.
Blocks may be resurfaced to the specifications shown in the
drawing, provided resurfacing will not reduce the block height
below the minimum specification. Table 3-7, Cylinder Block
Measurements.
BALL GUIDE AND SLIPPER RETAINER
Inspect the ball guide and slipper retainer for damage, discol-
oration, or excessive wear. A discolored ball guide or slipper
retainer indicates excessive heat. Do not reuse.
VALVE PLATE
The condition of the valve plate is critical to the efficiency of
the motor. Inspect the valve plate surfaces carefully for exces-
sive wear, grooves, or scratches. Replace or resurface grooved
or scratched valve plates. Measure the valve plate thickness
and replace if worn beyond the minimum specification. Valve
plates may be resurfaced to the specifications shown in the
drawing, provided resurfacing will not reduce the thickness
below the minimum specification.
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