TM 5-3805-280-24-2
Crankshaft, Main Bearings and Flywheel
CRANKSHAFT GRINDING GUIDELINES
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IMPORTANT: Crankshaft grinding should be done
ONLY by experienced personnel on
equipment capable of maintaining
crankshaft size and finish
specifications. Undercut and rolled
fillets (A) have taken the place of
ground (tangential) fillets. DO NOT
grind within this undercut area when
undersize bearings are used.
Crankshafts have micro-finished journal surfaces.
IMPORTANT: If undersize bearings are installed,
recheck bearing-to-journal clearance. If
oil clearance is not within
specifications, premature wear of
bearings and journals will result.
If the crankshaft is to be reground, use the following
recommended guidelines:
1. Compare the crankshaft journal measurements taken
during inspection and determine the size which the
journals are to be reground.
A--Fillets
2. Grind all main journals or all connecting rod journals to
the same required size.
IMPORTANT: Care must be taken to avoid localized
heating which often produces grinding
cracks. Use coolant generously to cool
the crankshaft while grinding. DO NOT
crowd the grinding wheel into the work.
Grind crankshaft with journals turning
counterclockwise, as viewed from the
front end of the crankshaft. Lap or
polish journals in opposite direction of
grinding.
3. Polish or lap the ground surfaces to the specified finish
to prevent excessive wear of the journals.
Continued on next page
RG,15,DT7437 1914NOV971/2
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