TM 10-3930-660-34 3-8. CRANKSHAFT - REPLACE/REPAIR (Cont’d) 4.   INSPECT MAIN BEARING BORES FOR DAMAGE OR ABNORMAL WEAR, PARA.  3-9. 5.   MEASURE DIAMETER OF MAIN BEARING BORES, PARA.  3-9. 6.   INSPECT AND MEASURE CONNECTING ROD BEARINGS, PARA.  3-15. ASSEMBLY 1.   INSTALL ROLL PIN (22) AND CRANKSHAFT GEAR (21). a. If a new crankshaft is being installed, a new roll pin (21) must be installed. CAUTION Do not heat crankshaft gear (21) longer than 45 minutes. The gear will become permanently distorted if it is heated for longer than 45 minutes. b. Heat crankshaft gear (21) in an oven for 45 minutes at 2500F. c. Wearing insulated gloves, install crankshaft gear (21), with timing mark facing you, onto crankshaft until it is against the shaft shoulder. 3-57