TM 10-3930-671-24 d. Ball or roller bearings should be placed in a basket and suspended in a container of dry cleaning solvent overnight. If  necessary,  use  a  soft-bristle,  nonmetallic  brush  to  remove  caked  grease  and  chips.  Avoid  rotating  the  bearing  before solid particles are removed to prevent damage to bearings.  After cleaning, immediately spin bearings in light lubricating oil to remove solvent.  Allow excess oil to drip off. e. Check all oil passages and cavities for cleanliness and freedom from foreign material.  A thin, flexible wire should be run through oil passages to make certain they are not clogged.  Individual passages that are dirty may be cleaned using a pressure spray gun and dry cleaning solvent. f. Clean electrical parts such as relays, switches, etc., with a lint-free cloth moistened with dry cleaning solvent. g. Clean exterior surfaces of the battery with a weak solution of  baking  soda  and  water.    Apply  the  solution  with  a soft-bristle, nonmetallic brush to remove corrosive buildup on the battery cable terminals. 3-5. GENERAL INSPECTION INSTRUCTIONS. Inspection  consists  of  checking  for  physical  distortions,  wear,  cracks,  and  pitting  and  checking  dimensions  of  parts  for compliance  with  requirements.    Clean  all  parts  before  inspection.    If  any  defect  is  found,  correct  it  as  outlined  under GENERAL REPAIR INSTRUCTIONS before assembly. a. Inspect  all  surfaces  in  contact  with  gaskets,  packings,  or  seals  for  nicks,  burrs,  scratches,  etc.,  which  might damage the new seal upon assembly. b. Examine bearings for rusted or pitted cones, balls, or cups.  Examine bearing cones and cups for abrasion and serious discoloration.  The following are causes for bearing rejection: (1) Cuts or grooves parallel to ball or roller rotation. (2) Fatigue pits (as opposed to minor machine marks or scratches). NOTE Defects  which  may  cause  bearing  binding  or  misalignment  are  cause  for  rejection.    Nicks  or gouges outside cup load areas are not cause for rejection. c. The following descriptions of wear conditions may help to determine when gear parts are performing satisfactorily: (1) Normal wear.  Loss of metal from surface of gear tooth resulting from unavoidable abrasion, but not to a degree that prevents gear from performing satisfactorily. (2) Initial pitting.  Pitting may occur when gears are first started in service.  It may continue only to a stage where high spots  have  been  reduced  and  there  is  still  enough  contact  area  to  carry  load  without  further  impairment.    This pitting is not necessarily serious. (3) Destructive pitting.  Pitting that continues to progress after initial period of operation, and to such a degree, that there  is  not  enough  contact  area  remaining  to  carry  the  load.    Rapid  destruction  may  occur  from  continued operation. (4) Abrasive  wear.    Surface  damage  caused  by  fine  particles  carried  in  lubricant  or  particles  imbedded  in  tooth surfaces.  Particles may be metal detached from gear tooth or bearings, abrasive not completely removed before assembly, sand or scale from casting, or other impurities in oil or surrounding atmosphere. 3-3