TM 10-3930-659-34 5-4. ENGINE MAIN BEARINGS, THRUST BEARING, AND CRANKSHAFT REPLACEMENT (Con’t). b. CLEANING AND INSPECTION WARNING 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 (380°C-590C). If you become dizzy while using cleaning solvent, immediately get fresh air and medical help.  If solvent contacts eyes, immediately wash your eyes and get medical aid. 1. Clean crankshaft and bearing caps with dry cleaning solvent and clean rags. WARNING Compressed air used for cleaning or drying purposes, or for clearing restrictions, should never exceed 30 psi (207 kPa). Wear protective clothing (goggles/shield, gloves, etc.) and use caution to avoid injury to personnel. 2. Flush oil passages of crankshaft with dry cleaning solvent and dry with compressed air. 3. Inspect crankshaft for scoring and overheating. Replace crankshaft if damaged. 4. Inspect crankshaft and journals for deep scratches and cracks. Replace crankshaft if damaged. 5. Inspect crankshaft keyway for damage and cracks. Replace crankshaft if keyway is damaged or cracked. 6. Inspect rear oil seal contact surface for deep scratches. Replace crankshaft if scratches cannot be smoothed with crocus cloth. 7. Using outside caliper micrometer, measure and note diameter of each crankshaft main bearing journal at several locations.  Diameter  must  be  3.1230-3.1240  in.  (7.9324-7.9350  cm).  If  measurement  is  not  within  specification, replace crankshaft. 8. Subtract  the  smallest  measurement  from  the  largest  measurement  taken  in  step  7.  Difference  between  the  two measurements is out-of-round. Out-of-round must be no larger than 0.0030 in. (0.0762 mm). If out-of-round is not within specification, replace crankshaft. 9. Using outside caliper micrometer, measure and note diameter at 1 in. (25.4 mm) intervals along length of journal beginning at one end  of  each  crankshaft  main  bearing  journal.  Difference  between  each  measurement  is  taper. Taper must be no larger than 0.0001 in. (0.0003 mm) per 1 in. (25.4 mm) of crankshaft main bearing journal. 5-38