SERVICE MANUAL CRANKSHAFT, MAIN BEARINGS, FLYWHEEL & CRANKCASE Section 6 4. Maintain   a   grinding   wheel   speed   of 6500   surface   feet   per   minute   with   a work   spindle   speed   of   approximately 40 to 45 RPM, for satisfactory results. CAUTION!      As   a   normal   precaution,   it   is recommended  that  a  CO2  fire  extinguisher  be  near the   grinding   machine,   just   In   case   any   excessive heat should ignite the oil.  If a fire should start, it can be rapidly extinguished without causing any damage to the machine or surrounding area by following the normal fire-extinguishing procedure. 5. Feed    rates    should    be    slower    than normal to prevent any burning. 6. Maintain   grinding   limits   as   shown   in Fig. 12. d. Allow  the  shaft  to  thoroughly  cool,  prior  to inspecting for dimensional tolerances. e. Prior  to  lapping  inspect  for  burning  during the   regrinding   procedure   with   TAROSOV ETCH as follows: CAUTION!        Due    to    the    sharp    odor    and flammability of the Tarosov Etch, the etching should be   done   In   a   well-ventilated   area,   away   from   any open flame. 1. Clean    the    surface    with    a    scouring powder and water or a good solvent. 2. Wash thoroughly and rinse with alcohol. 3. Apply etchant No. 1 (4 parts Nitric acid in 96 parts water) for approximately 16 seconds with a cotton swab. 4. Rinse with water and dry. 5. Apply etchant No. 2 (2 parts Hydrochloric acid in 98 parts acetone) for  approximately  15   seconds   with   a cotton swab. CAUTION!  Acetone Is highly flammable. 6. Rinse  with  alcohol  and  dry  thoroughly with compressed air. 7. TAROSOV  ETCH  will  show  up  as   a change of color after each etch,  if  the crankshaft   has   been   burned.      Areas rehardened  by  excessive  heat  appear nearly white, while softened areas turn a dark grey or black. Areas unaffected by the heat of grinding etch a light gray. SCRAP   THE   CRANKSHAFT   IF   ANY   BURNS SHOW UP AFTER ETCHING. f. After  grinding  and  lapping  visually  inspect the     surface     for     grinding     cracks,     using magnaflux on Elotherm crankshafts. SCRAP   THE   SHAFT   IF   ANY   SUR-FACE CRACKING IS FOUND. Inspect the Flywheel and Ring Gear as follows: 1. When used with clutches having bi-metallic-driven members examine the contact face of the flywheel for heat cracks and scoring.  Service or replace  if scoring is excessive. 2. When    used    with    clutches    having    ceremetallic- driven members, scoring of the flywheel is normal. However, if scoring is excessive reface or replace the flywheel as required. 3. Inspect the ring gear for broken teeth and replace it if necessary. CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 12