4-35. CRANKSHAFT MAINTENANCE (Cont)
Dry cleaning solvent P-D-680 is toxic and flammable. Wear protective
goggles and gloves and use only In a well-ventilated area. Avoid
contact with skin, eyes, and clothes and dont breathe vapors. Do not
use near open flame or excessive heat. The flash point is 100oF-138oF
(38°-50oC). If you become dizzy while using cleaning solvent, get fresh
air immediately and get medical aid. If contact with eyes is made, wash
your eyes with water and get medical aid immediately.
Compressed air used for cleaning purposes will not exceed 30 psi. Use
only with effective chip guarding-and personal protective equipment
(goggles/shieid, gloves, etc).
(1) Clean all crankshaft oil passages thoroughly with cleaning solvent and dry with compressed
(2) Clean front and rear crankshaft gears with cleaning solvent.
(1) inspect gear teeth for evidence of scoring, pitting, and wear. If severely damaged or worn,
(2) Inspect crankshaft keyways for evidence of cracks or wear. Replace crankshaft if required.
Replace crankshaft if it shows evidence of excessive overheating since heat
treatment has probably been destroyed.
Ridges on crankshaft journals must be removed. If ridges are not removed, localized
high unit pressures are placed on new bearing shells and short bearing life can
Inspect crankshaft journals for ridges and grooves. Ridges exceeding 0.0002 inch must be
Replace crankshaft if journal ridges are greater than 0.001 inch in depth.
(4) Remove crankshaft journal ridges by working crocus cloth, wet with fuel oil, around
circumference of journals. if ridges are greater than 0.0005 inch, first use 120 grit emery cloth
to clean up ridges, 240 grit emery cloth for finishing and wet crocus cloth for polishing.