(3)   Position   idler   gear   bearings   with spacer  between  them  in  idler  gear. NOTE (4)  Apply  a  light  coat  of  engine  oil  to  idler gear   shaft.   Position   idler   gear   with   bearings   on idler  shaft  making  certain  the  timing  marks  on  the idler  gear  and  the  crankshaft  gear  are  lined  up  prop- erly  when  number  1  piston  is  at  top  dead  center,  as illustrated  in  figure  14-25. (5)  Install  capscrew  with  washer  and tighten cap screw to a torque of 95 to 105 foot-pounds. NOTE The allowable end play of the idler gear  bearing  is  a  minimum  of 0.001  inch. c. Fuel  Pump  Drive  Gear  Installation. — (1)  Coat  fuel  pump  drive  shaft  with  engine oil  and  install  shaft  in  pump  mounting  adapter.  In- stall woodruff key. (2)  Position  drive  gear  on  drive  shaft  with  the keyway   lined   up   with   the   woodruff   key.   Install lockwasher  and  nut  on  drive  shaft  and  tighten  nut  to  a torque of 35 to 40 foot-pounds. NOTE During  the  assembly  of  the  engine  or replacement  of  any  of  the  timing  gears it  is  necessary  to  align  the  timing marks  as  shown  in  (fig.  14-25,  view  B). After  aligning  the  marks,  rotate  the flywheel  counter-clockwise  (view  from timing  gear  end)  until  the  proper  de- gree  timing  mark  (for  the  specified rpm) on the pulley and  damper assembly   is   registered   with   the pointer  on  the  front  of  the  timing gear  cover.  The  engine  is  now  prop- erly  positioned  for  the  installation  of the fuel pump. NOTE Check  backlash  between  all  gears. Backlash between any two mating gears  must  not  exceed  0.015  inch. New  parts  must  be  installed  if backlash   exceeds   this   requirement, Refer  to  para  14-74  for  replacement of  gears. O i l     S e a l . (1)  Clean  the  timing  cover  bore  to  receive a  new  seal. The  outer  diameter  of  the  front  oil seal  has  a  layer  of  red-colored  seal- ant  which  forms  a  seal  between  the outer  diameter  of  the  seal  and  the bore  in  the  cover.  The  bore  of  the seal  has  a  layer  of  rubber  compound to  prevent  oil  leakage  between  the seal  and  the  crankshaft. (2)  Place  timing  cover  on  a  flat  surface with  the  front  side  to  the  top. (3)  Position  seal  in  timing  cover  with  open side  of  seal  facing  down  and  positioned  squarely  in bore  of  cover. CAUTION Make  certain  that  seal  is  not cocked  in  timing  cover  bore. (4)  Drive  or  press  seal  into  timing  cover bore  until  it  bottoms. CAUTION Do not press on open face of seal or  damage  will  occur. (5)  After  seal  is  installed  in  the  cover,  in- sert  fingers  into  inner  part  of  seal  and  check  for rotation.   If   seal   was   installed   properly,   the   inner part  will  turn  with  a  firm  feel  to  the  fingers. e. Cover   Installation. — (1)  Inspect  and  remove  burrs  from  keyway in  crankshaft,  using  a  fine-cut  mill  file  or  stone,  to prevent  damaging  the  inner  layer  of  rubber  of  the crankshaft   oil   seal. (2)  Coat  crankshaft  lightly  with  engine lubricating   oil. (3)  Cement  (permatex  or  equivalent)  a  new gasket  to  the  timing  gear  cover. (4)  Using  a  direct  reversal  of  the  removal procedure,  position  the  gear  cover  on  the  two  dowel pins  in  the  cylinder  block  and  complete  the  installa- tion  of  the  cover  and  the  component  parts.  Tighten all   capscrews,   securing  the  cover  to  a  torque  of 28-33 foot-pounds. Also tighten the six  cap  screws securing  oil  pan  to  timing  gear  cover  to  a  torque  of 28-33 foot-pounds. f. Crankshaft    Pulley    Installation.    Install crankshaft  puIIey and vlbration  dampener    assembly. (para 14-63) Change 6 1 4 - 75