TM   9-2815-202-34 4-23.   REAR   OIL   SEAL   REPLACEMENT   (Cont) b.   Cleaning/Inspection (1) Clean flywheel housing seal bore. CAUTION Do not polish parallel to crankshaft or ridges will result and cause oil leakage. (2) Inspect rear end of crankshaft (4) for wear due to rubbing action of oil seal (5), dirt build up, or fretting by action of flywheel. Remove slight ridges from crankshaft  by  polishing  with  crocus cloth in circular motion. CAUTION Rotate  crankshaft  in  counterclockwise  direction  only.  Do  not  rotate  crankshaft  bolt clockwise  or  loosening  will  result. (3) Check runout of seal bore by mounting a dial indicator on crankshaft and note reading while crankshaft  is  rotated.  Measure  with  flywheel  housing  installed  on  engine  and  seal  removed. Maximum runout of bore is 0.008 inch. c.    Installation CAUTION l Crankshaft  surface  must  be  clean  and  smooth  to  prevent  damage  to  seal  lip  when  a new seal is installed. l Do not scratch or nick sealing edge of oil seal or oil leakage past seal will result. NOTE If new seal is not precoated, apply a nonhardening sealant to metal casing. (1) Coat lip of rear oil seal (5) with engine oil. (2) Install two guide studs (6) and oil seal expander (7) to end of crankshaft. (3) Position seal (5) with lip pointed toward inner face of housing. Slide seal over seal expander (7) and onto crankshaft. Remove seal expander and guide studs. (4) Using seal installer (8), guide studs (9), and driver handle (10), drive seal in place. (5) Remove seal installer (8) and guide studs (9). (6)  Remove  excess  sealant  from  flywheel  housing  or  seal. 4-78