TM 5-3895-374-24-2 location as in original assembly.  Before starting the  shafts  through  the  headplate  holes.    make sure shaft ends have no sharp or rough edges to damage  seal  lips.    Position  impellers  at  90°  to each  other  in  the  cylinder,  using  lobe-and-waist match  marks  if  original  impellers  are  being  re- installed.  Install drive end headplate and feet in same manner as gear end. 10.    It  is  recommended  that  new  bearings  be  used for rebuild.  Apply thin film of machine oil on the shaft   bearing   fit,   bearing   I.D.,   and   headplate bearing  bore.    Install  drive  end  bearings   into headplate.  Use a tube with flanged end that will contact    both    bearing    faces    simultaneously. Refer to Fig.  11 for proper bearing depths. NOTE:      Cylindrical   drive   bearing   should   be installed  with  inner  race  large  shoulder  facing outboard. 11.    Place   blower   on   its   feet   on   a   flat   surface. Loosen feet capscrews (32) and square up unit. Re-tighten capscrews (32).  Clamp unit down to a solid base for further assembly. 12.    Oil   the   gear   end   bearing   fits   as   described previously.    Install  2  1/2-5"  UNIVERSAL  RAI gear   end   bearings   flush   with   the   headplate bearing shoulders using proper drivers.  On 6" & 7" UNIVERSAL RAI®, install thrust  washer  (29) in  bearing  bores  then  install  gear  end  bearings so   that   they   protrude   1/16”   (1.6mm)   above headplate surface. 13.    Install  bearing  clamp  plates  (34).    On  6"  &  7" UNIVERSAL RAI®, impeller end clearances are also  to  be  set  during  this  step.    Install  clamp plates (34) with capscrews (31) making sure that the   gap   between   the   clamp   plates   and   the headplate is even all around, at the same  time, set end clearances per Table 5. 14.    Install gears and time impellers as in (A). 15.    For  setting  end  clearances  on  2  ½  -  5"  gear diameter units, special tools.  thrust adjuster fork Fig.    7  and  thrust  adjuster  saddle  Figure  8  are required.  Refer to Fig.  6 for installation of tools. The  flat  side  of  the  saddle  rests  against   the bearing  inner  race  and  the  flat  side  of  the  fork rests against the back side of the gear.  Install a shim, with thickness equal to gear end clearance (Table 6), between the impeller and the gear end headplates.  Tap on top of the fork until the shim becomes  snug.    Remove  the  shim  and  check end    clearances.          To     increase     gear     end clearance, tap on the end of the gear end shaft with a soft metal mallet.  On units, UNIVERSAL RAI. set   end   clearances   for   6"   &   7”   by   turning capscrews (31) evenly in or out. 16.    Install drive end cover (5) after packing  bearing cavities   with   suitable   grease.      Replace   drive shaft   seal.      Lip   must   point   toward   (33)   the bearing.  Exercise care not to damage the Lip as it passes over shaft keyway. 17.    Install  gasket  item  (7).    Install  the  gear  house after  cleaning  out  the  inside.    Tighten  gear  box cap screws (23) evenly.  Fill with correct grade of oil   until   oil   flows   out   through   oil   level   hole. Grease drive and bearings.  (See Lubrication.) 18.    Reinstall  coupling  or  belt  sheave  making  sure that they have a slight slide fit with the shaft and could be installed by hand. Where  repairs  involve  parts  replacement,  it  is recommended that Factory Parts be used to insure fit and suitability. Delay   in   making   such   repairs   can   be reduced by having spare parts on hand. When ordering parts, please furnish all information from the blower nameplate. Repairs  or  adjustments  to  blowers  should  be performed  by  personnel  with  a  good  back  ground  of general  mechanical  experience  and  the  ability  to  follow the detailed instructions in this manual. No   special   tools are required.  Some operations involve extra care and a degree of precision work.  This is especially true in timing impellers.      and   in   handling   bearings.      Experience indicates  that  a  high  percentage  of  bearing  failures  is caused by dirt contamination before or during assembly. Therefore,     clean     the     work     area     before     starting disassembly.   and  protect  new  or  reusable  parts  during progress  of  the  work.    (See  page  23   for   Repair   Kit Information.) INTERNAL CLEARANCES References    to    operating    clearances    in    this manual include only one mention of the specific amount of clearance to be used or expected. For  units  in  good condition this information is not essential in field service work.  Situations may arise, however, when it is desirable to    compare    existing    clearances    with    the    correct Engineering values or to reestablish clearances. Listed   in   Table   6   are   the   ranges   of   impeller clearances     used     in     factory     assembly     of     normal UNIVERSAL  RAI®  blowers.    It  should  be  kept  in  mind that   clearances   may   change   slightly   in   service,   but should  never  be  less  than  the  minimum  values  listed. Only well qualified personnel should attempt to measure clearances for direct comparison with this data. page  3 - 812