SERVICE MANUAL CRANKSHAFT, MAIN BEARINGS, FLYWHEEL & CRANKCASE Section 6 NOTE:    All  crankshafts  must  be  hardness  checked before    regrinding.        Bearing    failures    can    cause overheating    of    crankshaft    journals,    resulting    in reduction of hardness. 5. Inspect the crankshaft gear teeth and splined collar for wear and chipping.  Replace damaged parts as required. 6. Visually  inspect  the  drilled  holes  in  the  main  and connecting rod journals to assure that all passages are open after cleaning. Repair the Crankshaft as follows: Special precautions must be taken during grinding when regrinding   the   crankshaft.      The   following    MUST    be adhered  to  when  regrinding  or  the  crankshaft  can   be severely weakened: IMPORTANT:      All   466   Series   engines   have   fillet- hardened crankshafts. Take caution during grinding. NOTE:    Due  to  the  exacting  standards  and  controls for   shaft   regrinding,   it   is   recommended   that   this work  be  done  by  I.H.  ReNEWed  Stations.    However, regrind    locally    where    equipment    experience    can produce quality standards.  Proceed as follows: a. Check for hardness as described earlier in this section. b. Crankshafts may be straightened ac’-cording to following instructions: 1. Crankshaft  straightening  is required when main bearing journal runout is in excess of .007”  T.I.R.    checked  at  #4  main  bearing. 2. Check runout with #1 and #7 main  bearing  journal in  “V”  blocks    When  straightening,  support  crank- shaft on #1 and #7 main journals, straightened with the   deflection   of   #4   main   journal   limited   by   a positive stop to “A” (see chart). 3. Apply straightening force to #4 main journal. ENGINE "A" 300 Series .200" 400 Series .500" CAUTION! Crankshaft must be Magnaglo  or  Magnaflux  inspected  for  cracks  after straightening is completed.  Crankshaft must not be deflected  more  than  the  indicated  limit  at  #4  main journal.      Crank-shaft   must   be   demagnetized   after inspection. c. Grind     crankshaft     observing     the     following precautions: 1. Use   only   a   mechanical   or   an   automatic wheel  dresser  to  prevent  chatter,  burring and poor surface finish. 2. Select  the  appropriate  grinding  wheel.    An aluminum-oxide    wheel    with    a    50    grit surface  and  maximum  hardness  of  M,  is recommended  to  reduce  the  possibility  of burns during grinding. 3. Straight-cutting  oils  are  recommended  as the best coolant for grinding crankshafts. CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 10