SERVICE MANUAL CRANKSHAFT, MAIN BEARINGS, FLYWHEEL & CRANKCASE Section 6 CLEANING, INSPECTION & REPAIR CLEANING Clean the Crankshaft and Main Bearings as follows: 1. Clean all parts with non-caustic cleaning solvent. 2. Dry with compressed air. 3. Clean all the crankshaft internal oil passages of any dirt  or  sludge  that  may  have  accumulated.    Run  a stiff  wire  brush  through  the  oil  passages  to  loosen the  deposits,  then  wash  the  passages  and  external surfaces  of  the  crankshaft  thoroughly  with  fuel  oil. Blow  the  passages  and  external  surfaces  dry  with compressed air. Clean the Flywheel and Ring Gear as follows: 1. Wash   the   flywheel   and   ring   gear   in   non-caustic solvent. 2. Dry with Compressed air. Clean the Crankcase as follows: 1. During overhaul it is best to clean the crankcase in   a   chemical   “hot   tank.”      This   removes   all carbonous   material   and   mineral   deposits   that collect in the cooling passages. 2. Clean all lube oil passages, thoroughly. 3. Remove  gallery  plugs  and  swab  with  a  brush and solvent.  (Reseal all plugs upon installation). 4. Clean    all    threaded    holes    with    a    tap    of appropriate size and blow clean with compressed air. INSPECTION AND REPAIR Inspect    the    Crankshaft    and    Main    Bearings    as follows: 1. Visually inspect the bearings for wear and evidence of   uneven   bearing   support.      If   such   evidence   is found,   examine   the   bearing   caps   and   supporting surfaces of the crankcase for high spots and burrs. 2. Visually inspect the crankshaft journals for scoring. 3. Measure the diameter of each journal using a    micrometer    as    shown    in    Fig.        11. Measure each journal at two points, at right angles to each other.  Move the micrometer over the entire width of the journal.  Limits of: 85.705 mm (3.3742 in.) 85.738 mm (3.3755 in.) must be observed. Figure 11.  - Measuring the Crankshaft Journals 4. Check   HARDNESS,   on   every   journal   which incurred  a  bearing  failure  or  shows  evidence  of overheating, as follows: a. Using  a  Rockwell  Hardness  Tester,  check at least three locations. NOTE: Fillet hardened shafts should be checked as close  to  the  fillet  as  possible.    Non-fillet  hardened shafts  should  be  checked  at  least  13  mm  (1/2  inch) from the fillet. b. Check rod journals at top,  bottom  and  one other location.  (Top and bottom determined with journal at TDC). c. Minimum hardness: D-312, D and DT-360, D and DT-414, D and 30 RC DT-436 non-fillet hardened shafts. D, DT and DTI-466 45 RC fillet hardened shafts. If    any    reading    is    below    the    minimum hardness, REPLACE the crankshaft. CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 9