Mitsubishi 6M70 Workshop Manual page 103

Mitsubishi 6M70 Crankshaft undersize dimensions (Unit: mm)
Finished journal outside diameter
Finished pin outer diameter
Roundness
Cylindricity
Grinding of crankshaft
CAUTION
• If the crankshaft pins and journals are ground to undersiz-
es, be sure to use bearings of corresponding undersizes.
• Check the measurement in the table of service standards and
correct the crankshaft as follows.
• Do not change the center-to-center distance A between the
journal and pin.
• Do not change the journal width B and the pin width C.
• Finish the fillets D smoothly.
• Carry out a magnetic inspection to check for cracks possibly
caused by grinding. Also, check that the hardness of the sur-
face has not dropped below Shore hardness number (Hs) 75.
• If there is any abnormality, replace the crankshaft.
0.25 0.50
-0.08
99.75 99.50
-0.10
-0.06
83.75 83.50
-0.09
• When grinding, turn both the crankshaft and the grinder counter-
clockwise as viewed from the crankshaft front end.
• When finishing the crankshaft with whestone or sandpaper, ro-
tate the crankshaft clockwise.
Inspection: Distortion of crankcase top surface
• If the measurement exceeds the limit, correct the crankcase top
surface with a surface grinder.
CAUTION
• Do not grind the crankcase top surface so much as to com-
promise the correct piston protrusion.
Undersizes
0.75
-0.08 -0.08
99.25
-0.10 -0.10
-0.06 -0.06
83.25
-0.09 -0.09
0.01 or less
0.006 or less
11
1.00
-0.08
99.00
-0.10
-0.06
83.00
-0.09
11-93