TM 10-3930-660-34 3-18.  CAMSHAFT, CAMSHAFT GEAR, AND CAMSHAFT BUSHING - REPLACE (Cont’d) 2. INSPECT CAMSHAFT. a.   Inspect fuel lift pump lobe, valve lobes and camshaft bearing journal for cracking, pitting or other defects. b.   Measure bearing journal diameter. Minimum allowable diameter is 2.1245 in. (53.962 mm). c.   Measure valve lobe diameters at peak of lobe. Minimum allowable intake valve lobe diameter at peak of lobe is 1.852 in. (47.040 mm). Minimum allowable exhaust valve lobe diameter at peak lobe is 1.841 in. (46.770 mm). d.   Measure fuel lift pump lobe diameter. Minimum allowable fuel lift pump lobe diameter is 1.398 in. (35.5 mm). 3. INSPECT CAMSHAFT GEAR. a.   Discard camshaft gear if measured backlash (REMOVAL, Step la.) is not 0.003 to 0.013 in. (0.08 to 0.33 mm). b.   Inspect gear teeth for damage or excessive wear. c. Check for cracks at roots of gear teeth. 4. INSPECT THRUST PLATE. a.   Examine thrust plate for damage, distortion or excessive wear. b.   Discard thrust plate if measured camshaft end play (Removal, step 1a.) is not 0.007 to 0.011 in. (0.17 to 0.29 mm). Also check for enlarged thrust plate slot in camshaft if end play is excessive. 3-114