Kubota M9540, Workshop Manual, Page: 197 / 619

1-S74
M8540, M9540, WSM ENGINE
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
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
Replacing Small End Bushing
(When removing)
1. Press out the used bushing using a small end bushing replacing
tool.
(When installing)
1. Clean a new small end bushing and bore, and apply engine oil to
them.
2. Insert a new bushing onto the tool and press-fit it with a press so
that the seam (1) of bushing position as shown in the figure, until
is flash with the connecting rod.
W1066057
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.
Oil clearance between
piston pin and small end
bushing
Factory spec.
0.020 to 0.040 mm
0.00079 to 0.0015 in.
Allowable limit
0.15 mm
0.0059 in.
Piston pin O.D. Factory spec.
30.006 to 30.011 mm
1.1814 to 1.1815 in.
Small end bushing I.D. Factory spec.
30.031 to 30.046 mm
1.1824 to 1.1829 in.
(1) Seam (A) When Removing
(B) When Installing
(C) 0.26 rad (15 °)
KiSC issued 09, 2008 A