TM9-2815-226-34-1 - JATONKAM35s HOME ON THE WEB

TM 9-2815-226-34-13-14. REPAIR CRANKSHAFTa. Buff all minor nicks and scratches with crocus cloth.b. If inspection shows crankshaft is worn to a point where it must be reground and magnetic inspection shows itsuitable for regrinding, grind shaft to next standard undersize (table 3-1).c. If crankshaft thrust face is worn, grind as necessary to accept larger thrust rings.d. Fillets add strength to crankshaft. Reducing fillet radii or undercutting subtracts material from that strength. Iffillets are larger than those specified, bearing shells may be squeezed and will quickly fail.e. Grind width of journals to clean up basic face surface.(1) If there are deep interruptions such as gouges or nicks that do not extend into fillets, smooth the edges withcrocus cloth.(2) Maintain a limit of 0.030 in. (0.762 mm) over the maximum new crankshaft main bearing width specification(table 3-1).(3) The journal wall heights are not to be lowered to less than 0.010 in. (0.254 mm) from journal cheeks inregrinding journal bearing widths.(4) All fillet and bearing surfaces should have the same finish as a new crankshaft.f. Crankshafts requiring "off-strike" grinding to clean up an unusually bad out-of-round crankpin can be ground offstrokea maximum of 0.020 in. (0.508 mm) over or under mean stroke dimension of new crankshaftspecifications. All crankpins must be reground to the degree of "off-stroke" required by the most out-of-roundcrankpin.g. Install the crankshaft gear.WARNINGUSE GLOVES TO PROTECTED HANDS. HANDLE GEAR WITH CARE.CAUTIONDO NOT USE CUTTING TORCH TO HEAT GEAR. OVERHEATING OF GEAR WILLREMOVE HARDNESS CAUSING EARLY FAILURE.(1) Heat the gear with heating torch (not a cutting torch) to 400° F (204 C) for minimum of 1 hour.(2) Lubricate the flange with grease and drive the gear onto the shaft with a piece of tubing.3-125