Kubota WSM STa-30, Workshop Manual

Page: 105 / 359

1-S43
ST
α
-30 · ST
α
-35, WSM ENGINE
Oil Clearance between Crankpin and Crankpin Bearing
1. Clean the crankpin and crankpin bearing.
2. Put a strip of plastigage (Code No.: 07909-30241) on the center
of the crankpin in each direction as shown in the figure.
3. Install the connecting rod cap and tighten the connecting rod
screws to the specified torque, and remove the cap again.
4. Measure the amount of the flattening with the scale, and get the
oil clearance.
5. If the oil clearance exceeds the allowable limit, replace the
crankpin bearing.
6. If the same size bearing is useless because of the crankpin wear,
replace it with an undersize one referring to the table and figure.
NOTE
■
• Never insert the plastigage into the crankpin oil hole.
• Be sure not to move the crankshaft while the connecting rod
screws are tightened.
(Reference)
• Undersize crankpin bearing
• Undersize dimensions of crankpin
W1033106
Oil clearance between
crankpin and crankpin
bearing
Factory spec.
0.025 to 0.087 mm
0.00098 to 0.00343 in.
Allowable limit
0.2 mm
0.0079 in.
Crankpin O.D. Factory spec.
46.959 to 46.975 mm
1.84878 to 1.84941 in.
Crankpin bearing I.D. Factory spec.
47.000 to 47.046 mm
1.85039 to 1.85220 in.
Undersize Bearing Code Number Marking
0.2 mm
0.008 in.
Crankpin bearing 02 17331-22970 020 US
0.4 mm
0.016 in.
Crankpin bearing 04 17331-22980 040 US
Undersize
Dimension
0.2 mm
0.008 in. 0.4 mm
0.016 in.
A
3.3 to 3.7 mm radius
0.1299 to 0.1457 in. radius 3.3 to 3.7 mm radius
0.1299 to 0.1457 in. radius
B
1.0 to 1.5 mm radius
0.0394 to 0.0591 in. radius 1.0 to 1.5 mm radius
0.0394 to 0.0591 in. radius
C
46.759 to 46.775 mm
1.84091 to 1.84154 in. 46.559 to 46.575 mm
1.83303 to 1.83366 in.
(0.8-S)
The crankpin must be fine-finished to higher than
∇∇∇∇
KiSC issued 11, 2006 A