TM 10-3930-669-34 VISUAL INSPECTION (1) Remove front cover (Para 3-10). (2) Inspect oil tube for damage and looseness. (a) If  oil  tube  is  loose  or  damaged.  tighten connections or replace oil tube (Para 3- 12). (b) If  oil  tube  is  not  loose  or  damaged,  oil tube is OK. VISUAL INSPECTION (1) Set engine No. 1 piston to TDC (TM 10-3930- 669-20). (3) Install  guage  and  rotate  engine  180’  (TM  10- 393-669-20)    and    measure    oil    pump    gear backlash. (a) If gear backlash is not 0.0039 to 0.0079 in.   (0.1-0.2   mm),   replace   oil   pump   or engine (Para 3-12 or 3-3). (b) If gear backlash is 0.0039 to  0.0079  in. (0.1-0.2    mm),    oil    lube    pump    is    OK. 2-27