Kubota M5040 Workshop Manual page 194

M5040, M6040, M7040, WSM
Oil Clearance between Crankpin and Crankpin Bearing
1. Clean the crankpin and crankpin bearing.
2. Put a strip of plastigage on the center of the crankpin.
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.
Crankpin O.D. Factory spec.
Factory spec.
Oil clearance between
crankpin and crankpin
bearing
Allowable limit
IMPORTANT
• STD size crankpin bearing.
To replace it with a specific STD service part, make sure the
crankpin bearing has the same ID color as the connecting
rod.
Connecting rod
ID Color
Large-end in. dia.
53.01 to 53.02 mm
Blue
2.0870 to 2.0874 in.
Without 53.00 to 53.01 mm
color 2.0866 to 2.0870 in.
(Reference)
• Undersize dimensions of crankpin
0.2 mm
Undersize
0.008 in.
3.3 to 3.7 mm radius
Dimension A
0.1299 to 0.1457 in. radius
1.0 to 1.5 mm relief
*Dimension B
0.0394 to 0.0591 in. relief
49.780 to 49.791 mm dia.
Dimension C
1.9598 to 1.9603 in. dia.
The crankpin must be fine-finished to higher than ∇∇∇∇.
*Holes to be de-burred and edges rounded with 1.0 to 1.5 mm
(0.0394 to 0.0591 in.) relief.
(1) Connecting Rod Cap
(2) Connecting Rod Screw
(3) ID Color
1-S68
49.980 to 49.991 mm
1.9677 to 1.9682 in.
0.017 to 0.048 mm
0.0007 to 0.0019 in.
0.20 mm
0.0079 in.
Crankpin bearing
Class Part code Center wall thick
1.496 to 1.501 mm
L 1G772-22310
0.0589 to 0.0591 in.
1.491 to 1.496 mm
S 1G772-22330
0.0587 to 0.0589 in.
0.4 mm
0.016 in.
3.3 to 3.7 mm radius
0.1299 to 0.1457 in. radius
1.0 to 1.5 mm relief
0.0394 to 0.0591 in. relief
49.580 to 49.591 mm dia.
1.9520 to 1.9524 in. dia.
(0.8S)
(4) Crankpin Bearing
(5) Center Wall Thick
ENGINE
W1067389
KiSC issued 06, 2008 A