TM 10-3930-660-34 9-5 .  BEAR DIFFERENTIAL CARRIER ASSEMBLY - REPLACE/REPAIR/ADJUST (Cont’d) a. Apply marking compound to 12 gear teeth of ring gear. Rotate ring gear so that 12 gear teeth are next to bevel pinion. b. Rotate ring gear (18) forward and backward so that 12 marked teeth go past bevel pinion six times to get contact patterns .  Repeat ,  if necessary ,  to get a clearer pattern. c. Inspect contact patterns on ring gear (18) .  Good hand rolled pattern (H) will show contact toward toe of gear tooth and in the center between top and bottom of tooth .  A high pattern (I) will show contact closer to top of gear tooth .  A low pattern (J) will show contact toward bottom of gear tooth .  When in operation ,  pattern will extend to approximately full length of gear tooth. d. If necessary ,  install thinner shim pack (34) under pinion bearing cage (30) to correct high contact pattern. e. If necessary ,  install thicker shim pack (34) under pinion bearing cage (30) to correct low contact pattern. f. If necessary ,  decrease backlash , STEP 3 ,  g .  to move contact patterns toward toe of ring gear teeth. g. If necessary ,  increase backlash , STEP 3 ,  f .  to move contact patterns toward heel of ring gear teeth. h. Install two new cotter pins (11) that hold two bearing adjusting rings (12) in position .  Install cotter pins (11) through boss of bearing cap (10) and between lugs of adjusting ring (12). 9-29