TM 10-3930-671-24 A. Bearings 1. Wash all bearings in clean solvent.  Check balls, cages   or   retainers,   rollers   and   raceways   for pitting, discoloration and spalled areas.  Replace bearings that are pitted, discolored or spalled. 2. Always replace bearing cups and cones as a set. Do not replace a bearing or race separately. 3. Lubricate bearings that are not pitted, discolored or    spalled    and    check    for    axial    and    radial clearances. 4. Replace bearings with excessive clearances. 5. Check  bearing  fits.    Bearing  inner  races  should be   tight   to   shaft;   outer   races   slightly   tight   to slightly  loose  in  housing  bore.    If  bearing  spins freely    in    bore,    however,    housing    should    be replaced. 6. After inspection, lubricate bearings with clean oil and  wrap  in  a  lint-free  cloth  or  clean  paper  to protect them until installation. B. Gears and Shafts 1. Check     gear     teeth     for     frosting     and     pitting. Frosting of gear tooth faces presents no threat of transmission failure. Often in continued operation of the unit, frosted gears will "heal" and not  progress  to  the  pitting  stage.    And  in  most cases,  gears  with  light  to  moderate  pitted  teeth have  considerable  gear  life  remaining  and  can be    reused.        But    gears    with    advanced-stage pitting should be replaced. 2. If Magnaflux process is available, use it to check parts for damage. 3. If    gear    teeth    show    areas    where    the    case- hardening  is  worn  through  or  cracked,  the  gear must be replaced. 4. Inspect all shafts to be sure they are not bent or cracked and that splines are not damaged. C. Splines Check    splines    on    all    shafts    and    gears    for abnormal  wear.    If  splines  are  severely  worn  or pitted, replace the specific part affected. D. Reverse Idler Gear Assemblies Check  for  excessive  wear  from  action  of  roller bearings. E. Clutch Plates 1. Inspect clutch plates for excessive wear (shown by   worn   dimples   or   friction   surfaces)   and   for evidence   of   excessive   heating   of   plates   (blue color   indicating   excessive   heating)   or   warped plates. 2. Examine  clutch  disc  internal  and  external  teeth for evidence of excessive wear. 3. All  damaged  plates  must  be  replaced  with  new plates. F. O-Rings and Gaskets 1. Check    all    O-rings    for    cracks    or    distortion. Replace if worn.  It is good practice to replace all O-rings at overhaul. 2. Replace all gaskets at overhaul. 3. O-rings   and   seals   should   be   lubricated   with transmission fluid before assembly. G. Oil Seals 1. Check  oil  seals  for  nicks,  wear  and  breaks.    If sealing action of lip has been destroyed, replace seal.  It is good practice to replace all oil seals at overhaul. 2. Extra   care   should   be    used    when    seals    are installed  to  prevent  damage  to  the  seal.    Seal lips  and  sealing  surfaces  can  be  easily  nicked and   damaged,   thereby   destroying   the   sealing ability. H. Housings Check   all   housings   for   damage,   cracks   and wear.  Replace damaged housings, as needed. I. Capscrews,   Threaded   Fasteners   and   Snap Rings 1. Inspect    all    fasteners    for    damage    and    wear. Replace all damaged fasteners. 2. Snap rings are to be installed with flat side away from  load.    Replace  any  damaged  or  suspect snap rings. F-343