TM 5-3895-374-24-2 4. INSTALLATION:        Place    impellers    in    correct position  as  previously  marked.    Be  sure  shafts and gear bores are clean and free of scratches. Clean  the  shaft  tapered  fits.    Place  hardwood wedges as shown in Figure 5.  Install drive gear (4) and gear nut (17) so match  mark  at  tooth  is at  the  line  of  engagement.    Tighten   the   drive gear nut to the torque given in Table 5.  Blower assembly  must  be  fastened  down  for  torquing operation. TABLE 5 --GEAR NUT TORQUE Gear Size Torque (in.) lb.-ft. (kg-m) 2.5 60 ( 8.3) 3.5 110 (l5.2) 4.0 190 (26.3) 5.0 250 (34.6) 6.0 400 (55.3) 7.0 550 (76.1) 5. Installing  driven  gear  (4)    Insert  a  long,  metal feeler gauge between the impellers’ lobes at the fronts  or  backs  as  shown  in  Figure  5.    Feeler gauge thickness to be a middle value from Table 6  for  fronts  and  backs.    Align  the  gear  so  the tooth  match  marks  agree  with  the   drive   gear, then install nut (17).  Tighten lightly with a small wrench,  then  check  front  and  back  clearances against  Table  6  for  each  45°  position.    Both fronts and backs should be about the same and within  the  specified  range  in  Table  6.    Adjust gear   position,   if   necessary,   then   insert   the corrected  feeler  gauge  and  wedges  and  use  a torque  wrench  to  tighten  the  gear  nut  to   the torque  specified  in  Table  5.    Remove  wedges and rotate the drive shaft by hand to make sure there    are    no    gear    tight    spots    or    impeller contacts. Caution!   Keep   fingers   away   from   impellers and gears. 6.    Check   the   end   clearances   between   impellers and   headplates.      Adjust   clearances   per   B-15 below. 7.    When   clearances   are   correct,   clean   and   re- install the gearhouse.  Check condition of flange gasket   (7)   and   replace   if   questionable.      Fill gearhouse  to  correct  level  with  proper  grade  of oil. B -- Replacing Shaft Bearings and Impellers Remove coupling or sheave from the drive shaft. Drain and remove gearhouse, and pull the timing gears. If  gears  are  to  be  re-used,  mark  them  so  they  may  be returned to the same shafts. 1.    Break corners and deburr the keyway.  Remove bearing  end  cover  at  the  drive  end.    Remove bearing clamp plates (34). 2.    Make single and double identifying punch marks on the mating edges of headplate and cylinder flanges at the two ends of the blower. 3.    At  the  drive  end,  drive  out  the  two  dowel  pins  and remove all capscrews holding headplate to cylinder. By  inserting  jacking  screws  into  the  two  threaded flange holes, and turning them in evenly.the headplate  will  be  separated  from  the  cylinder.    As the   headplate   comes   off   the   shafts   it   will   bring bearings with it.  2 1/2" and 3 ½” gear diameter units do  not  have  tapped  holes  for  jack  screws  in  the drive  end  headplates.    Remove  dowel  pins  and  all capscrews holding headplate to cylinder and foot on the drive end.  Support unit under gear end cylinder flange  with  the  shafts  vertical.    Using  soft  metal block  against  gear  end  shafts,  push  them  out  of gear end headplate. 4.    For 21/2" and 3/2 " gear diameter units, support the drive  end  headplate  on  the  underside,  and  using soft  metal  block  against  drive  end.    shafts,  push them  out  of  drive  end  headplate.    For  4",  6"  &  7" gear  diameter  units,  from  the  gear  end  .,  using  a wood  or  soft  metal  block  against  the  ends  of  the shafts, drive them out of the headplate.  If they are to  be  reused,  protect  them  from  damage  in  this operation. 5.    If blower interior surfaces need cleaning, it may be advisable to separate the gear end headplate from the  cylinder.    Use  the  same  general  procedure  as employed at the drive end. 6.    Working from the back (flat) face of each headplate. push  or  tap  out  the  bearings  and  seals.    Use  a round  bar  or  tube  that  will  pass  through  the  shaft clearance holes in the headplates.  All lip seals will be damaged during removal and must be replaced. 7.    Clean  bearing  and  seal  pockets  in  headplates  and remove burrs or rough edges.  (Apply a thin coating of sealant on seal O.D.) Press new seals 127) into gear end headplate using a round tube or bar with recessed end that will bear on the outer metal edge of seal enclosure.  Seal lip should point toward the driving  tool.    Seals  to  be  flush  with  outboard  bore face.  Apply a light coat of oil or grease to the seal lips.    In  a  similar  fashion,  install  lip  seals  into  the drive end headplate. 8.    Place cylinder on a flat surface.  Assemble gear end headplate  to  cylinder  after  checking  flange  punch marks.  Drive in the two locating dowel pins before tightening flange screws.  Also install gear end foot using the same longer cap screws (32) and washers (411.  (on 6" & 7" UNIVERSAL RAI! install both gear and  feet.)  9.    Place  the  assembly  horizontally  on steel  blocks  with  gear  end  headplate  on  bottom. The height of the blocks should be sufficient to clear gear end shaft extensions.  Assemble impellers into the  cylinder  with  the  drive  shaft  (longer  shaft)  in same page 3-811