ARMY TM 9-2815-255-24
AIR FORCE TO 38G1-95-2
MARINE CORPS TM 2815-24/4
To maintain the correct end play, the two piece main bearing with three piece thrust washer set
can be used to replace the two piece flanged main bearings if desired.
Compare crankshaft journal measurements taken during inspection and determine size which journals are to be
If one or more main or connecting rod journals requires grinding, then grind all of main journals or all of
connecting rod journals to same required size. Grind clockwise (opposite engine rotation).
AD journal fillets radii must be free of any sharp grind marks or scratches. Fillet must blend smoothly into journal
and crank cheek. Radius may be checked with a fillet gage.
Care must be taken to avoid localized heating which often produces grinding cracks. Use coolant generously to
cool crankshaft while grinding. Do not crowd grinding wheel into work.
Polish or lap (counterclockwise) ground surfaces to specified finish. Reground journals will be subject to
excessive wear unless polished smooth.
When thrust surfaces are reground and an oversize washer is used, crankshaft end play
specification must be maintained.
If thrust surfaces of crankshaft are worn or grooved excessively, they must be reground and polished. Care must
be taken to maintain specified radius between each thrust surface and bearing journal. An oversize thrust
washer set is available.
Stone edge of all oil holes in journal surfaces smooth to provide a radius of approximately 0.060 inch (1.50 mm).
After grinding has been completed, inspect crankshaft by fluorescent magnetic particle method, or other similar
method to determine if cracks have originated due to grinding operation.
Cleaning solvent Is flammable and toxic to eyes, skin, and respiratory tract Skin/eye protection
required. Avoid repeated/prolonged contact. Good general ventilation Is normally adequate.
Compressed air used for cleaning can create airborne particles that may enter the eyes Pressure
will not exceed 30 psig (207 kPa). Eye protection required.
Thoroughly dean crankshaft and oil passages with dry cleaning solvent (P-680). Dry with compressed air.