TM  10-3930-638-24&P 4-2.   ENGINE   MAINTENANCE   (cont) g. Camshaft and Bearings (cont). STEP LOCATION ITEM ACTION REMARKS INSPECTION   AND   REPAIR 8 Camshaft  (9) a.  Overall Inspect Check  surfaces  for  wear,  damage,  and scoring. If any of these conditions observed,  replace  camshaft b.  Bearing  surfaces Measure front Use micrometer. Measure each bearing sur- and  rear face in four places. Measure front and rear surfaces again, 90 degrees from first measurement.  If  outer  diameter  of  any bearing surface is less than 1.748 inches, replace  camshaft. 9 Camshaft a. Overall Inspect Replace if cracked, damaged or worn thrust  plate b.  Thickness Measure Use  micrometer.  Replace  if  thickness  is (8) less than 0.147 inches 10 Camshaft  gear  (6) Inspect Replace if cracked, or if teeth damaged or missing 11 Valve  tappet a. Overall Inspect Replace if cracked, damaged or worn (3) b. Stem Measure Replace if less than 0.5605 inch outer  diameter 12 Cylinder  block, a. Valve tappet Measure Use bore gage. Replace cylinder block if bottom bores inside diameter greater than 0.5650 inch b. Camshaft Measure   inside Use bore gage and measure in two places, bushings  (10, diameter 90 degrees apart. Replace if greater than 11, and 12) 1.755  inches 4-55