Kubota M5640SU Workshop Manual page 145

M5640SU, M5640DT-SU, WSM
Crankshaft Alignment
1. Support the crankshaft with V blocks on the surface plate and
set a dial indicator with its tip on the intermediate journal at right
angle.
2. Rotate the crankshaft on the V blocks and get the misalignment
(half of the measurement).
3. If the misalignment exceeds the allowable limit, replace the
crankshaft.
Crankshaft alignment Allowable limit
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 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.
Factory spec.
Oil clearance between
crankpin and crankpin
bearing
Allowable limit
Crankpin O.D. Factory spec.
Crankpin bearing I.D. Factory spec.
(Reference)
• Undersize crankpin bearing
Undersize Bearing
0.2 mm
Crankpin bearing 02
0.008 in.
0.4 mm
Crankpin bearing 04
0.016 in.
• Oversize dimensions of crankshaft journal
0.2 mm
Undersize
0.008 in.
3.30 to 3.70 mm radius
Dimension "A"
0.130 to 0.145 in. radius
1.00 to 1.50 mm radius
Dimension "B"
0.0394 to 0.0590 in. radius
46.759 to 46.775 mm
Dimension "C"
1.8409 to 1.8415 in.
The crankpin must be fine-finished to higher than Rmax = 0.8S.
1-S57
ENGINE
0.02 mm
0.00079 in.
9Y1210365ENS0070US0
0.025 to 0.087 mm
0.00099 to 0.0034 in.
0.20 mm
0.0079 in.
46.959 to 46.975 mm
1.8488 to 1.8494 in.
47.000 to 47.046 mm
1.8504 to 1.8522 in.
Code Number Marking
17331-22970 020 US
17331-22980 040 US
0.4 mm
0.016 in.
3.30 to 3.70 mm radius
0.130 to 0.145 in. radius
1.00 to 1.50 mm radius
0.0394 to 0.0590 in. radius
46.559 to 46.575 mm
1.8331 to 1.8336 in.
9Y1210365ENS0071US0
KiSC issued 07, 2009 A