TM 10-3930-660-34 3-9.  CRANKSHAFT MAIN BEARINGS - REPLACE (Cont’d) CAUTION If crankshaft is turned in the wrong direction, the   tab   on   the   upper   bearing   half   will   be pushed   between   the   crankshaft   and   main bearing bore in the block.  This could cause damage to the block and the crankshaft. e. Remove number 7 main bearing, REMOVAL STEPS 2b through 2f. NOTE When  bearings  are   reused,   each   bearing must   be   installed   in   its   original   location because the bearing surfaces have worn to the crankshaft journals. 5. CLEAN     AND INSPECT NUMBER 1 AND NUMBER     7     MAIN     BEARINGS,     CLEANING STEPS 1 AND 2, INSPECTION STEPS  1,  3,  4, AND 5. 6. CHECK NUMBER 1 MAIN BEARING (3 AND 4) CLEARANCE. a. If main bearings are coated with oil, remove oil with a clean wiping rag. CAUTION To   help   prevent   damage   to   the   cylinder block   during   main   bearing   bore   cleaning, compressed  air  shall  not  exceed  15  psig. Use compressed air only with effective chip guarding and personal protective equipment. b. Clean main bearing surfaces in the cylinder block    and    bearing     caps     with     cleaning solvent  P-D-680.    Dry  surfaces  thoroughly with  low  pressure  compressed  air  (15  psig max.). 3-76