TM 9-2320-289-34
3-15. CRANKSHAFT, MAIN BEARINGS, AND FLYWHEEL REMOVAL (Con’t).
b. CLEANING AND INSPECTION
WARNING
l Dry cleaning solvent P-D-680 is toxic and flammable. Always wear
protective goggles and gloves and use only in a well-ventilated area.
Avoid contact with skin, eyes, and clothes and DO NOT breathe vapors.
DO NOT use near open flame or excessive heat. The solvent’s flash
point is 100°F-138°F (38°C-59°C). If you become dizzy while using
cleaning solvent, immediately get fresh air and medical help. If solvent
contacts eyes, Immediately wash your eyes with water and get medical
aid.
• Compressed air used for cleaning purposes should never exceed 30 PSI
(207 kPa). Use only effective chip guarding and personnel protective
equipment (goggles/shield, gloves, etc.). Failure to follow this warning
may result in serious injury to personnel.
1. Wash crankshaft (3) in dry cleaning solvent and dry with compressed air.
2. Wipe oil from rear main seal grooves in engine block and rear main bearing cap (5). Remove
all rear main seal material from mating surfaces.
WARNING
Carburetor cleaning compound is highly flammable, Keep away from open
flame. Failure to follow this warning may result in serious injury or death to
personnel.
3.
Using carburetor cleaning compound, clean bearing caps, rear main seal grooves, and
surface of engine block that mates with rear main bearing cap.
4.
Measure diameter of main journals (13) at several points and compare readings. Maximum
difference in diameter (out-of-round) should be 0.001 in. (0.025 mm). Replace crankshaft if
any main journal is beyond specifications.
5.
Measure diameter of main journals (13) at each end and middle and compare readings.
Maximum difference between ends and middle (taper) should be 0.001 in. (0.025 mm).
Replace crankshaft if any main journal is beyond specifications.
NOTE
Production diameter of rear main journal is 2.9493-2.9502 in.
(74.91 2-74.936 mm). All other main journals are 2.9495-2.9504 in.
(74.917-74.914 mm),
6.
Using measurements found in steps 4 and 5, determine if main journals (13) are undersized.
Minimum allowable diameter is 2.947 in. (74.874 mm) for rear main journal and 2.948 in.
(74.879 mm) for all other main journals. Replace crankshaft if any main journal is less than
minimum allowable diameter.
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