Kubota M5040, Workshop Manual

Page: 190 / 559

1-S64
M5040, M6040, M7040, WSM ENGINE
(3) Piston and Connecting Rod
Piston Pin Bore I.D.
1. Measure the piston pin bore I.D. in both the horizontal and
vertical directions with a cylinder gauge.
2. If the measurement exceeds the allowable limit, replace the
piston.
W1065759
Oil Clearance between Piston Pin and Small End Bushing
1. Measure the O.D. of the piston pin where it contacts the bushing
with an outside micrometer.
2. Measure the I.D. of the piston pin bushing at the connecting rod
small end with a cylinder gauge.
Calculate the oil clearance.
3. If the clearance exceeds the allowable limit, replace the bushing.
If it still exceeds the allowable limit, replace the piston pin.
W1065897
Piston pin bore I.D.
Factory spec.
28.000 to 28.013 mm
1.1024 to 1.1029 in.
Allowable limit
28.05 mm
1.1043 in.
Oil clearance between
piston pin and small end
bushing
Factory spec.
0.020 to 0.040 mm
0.0008 to 0.0016 in.
Allowable limit
0.15 mm
0.0059 in.
Piston pin O.D. Factory spec.
28.006 to 28.011 mm
1.1026 to 1.1028 in.
Small end bushing I.D. Factory spec.
28.031 to 28.046 mm
1.1036 to 1.1042 in.
KiSC issued 06, 2008 A