TM 10-3930-671-24 When the pump is removed and disassembled, examine the  impellers,  cover,  and  cavity  for  wear;  inspecting  the key  and  keyway  at  the  same  time.    If  scored  or  worn badly they must be replaced. Examine the pick-up screen for clogging or damage. Examine   the   O-Ring   at   the   pump   inlet.      If   damaged, replace.          Two     O-Rings     are     required     after     S/N 88096321. Engine  oil  pressure  must  be  maintained  to  specification for satisfactory engine life. The  oil  pump  must  be  fully  seated  in  the  counterbore. No gaskets are used in this assembly. Install  mounting  cap  screws  and  tighten  to  15-18  lb-ft (20-24 N•m) NOTE When   replacing   any   oil   pumps   on engines   built   before   SIN   88096321, the oil suction tube must be replaced also. TIMING GEARS 1. Timing gears should be inspected for excessive wear and/or pitting and replaced if necessary. F-183