Kubota M108S, Workshop Manual

Page: 183 / 523

1-S60
M108S, WSM ENGINE
Connecting Rod Alignment
NOTE
■
• Since the I.D. of the connecting rod small end bushing is the
basis of this check, check the bushing for wear beforehand.
1. Remove the piston pin from the piston.
2. Install the piston pin in the connecting rod.
3. Install the connecting rod on the connecting rod alignment tool.
4. Put a gauge over the piston pin, and move it against the face
plate.
5. If the gauge does not fit squarely against the face plate, measure
the space between the pin of the gauge and the face plate.
6. If the measurement exceeds the allowable limit, replace the
connecting rod.
W1066581
Piston Ring Gap
1. Insert the piston ring into the lower part of the liner (the least worn
out part) with the piston.
2. Measure the ring gap with a feeler gauge.
3. If the gap exceeds the allowable limit, replace the piston ring.
W1066430
Clearance between Piston Ring and Groove
1. Remove carbon from the ring grooves.
2. Measure the clearance between the ring and the groove with a
feeler gauge or depth gauge.
3. If the clearance exceeds allowable limit, check the new ring since
compression leak and oil shortage result.
4. If clearance still exceeds the allowable limit after replacing the
ring, replace the piston.
W1066183
Connecting rod
alignment
Allowable limit
0.05 mm
0.002 in.
Top ring and second ring
Factory spec.
0.30 to 0.45 mm
0.012 to 0.017 in.
Allowable limit
1.25 mm
0.0492 in.
Oil ring
Factory spec.
0.25 to 0.45 mm
0.0099 to 0.017 in.
Allowable limit
1.25 mm
0.0492 in.
Factory spec.
Top ring
0.05 to 0.09 mm
0.002 to 0.003 in.
Second ring
0.0930 to 0.120 mm
0.00366 to 0.00472 in.
Oil ring
0.020 to 0.060 mm
0.00079 to 0.0023 in.
Allowable limit
Top ring
0.15 mm
0.0059 in.
Second ring
0.20 mm
0.0079 in.
Oil ring
0.15 mm
0.0059 in.
KiSC issued 06, 2007 A