(17)Crankshaft  bearings  (22a,  35  and  39)  for  wear and scoring.  Refer to Table 6-1. (18)Oil   pump   (53),   shaft   and   gearwheel   (52)   for wear. (19)Figure 8-30, Sheet 3 of 10.  Control rod springs (54,  55a  and  56).    Connecting  lever  (55), governor lever (58) and control rod (59) for wear or damage. (20)Crankshaft  (45,  Figure  8-30,  Sheet  4  of  10)  for wear and scoring.  Refer to Table 6-1. d. Repair  or  Replacement.    Refer  to  paragraph  6- 3.c for general repair or replacement instructions. (1) Replace     parts     that     do     not     meet     the dimensional tolerances listed in Table 6-1. (2) Replace  cylinder  head  covers  (4,  Figure  8- 30,  Sheet  7  of  10)  with  damaged  contact surfaces. (3) Replace defective rocker arm bushings (20, Figure 8-30, Sheet 7 of 10). (4) Replace defective adjusting screws (19). (5) Replace defective rocker arms (17 or 23). (6) Replace defective rocker arm bracket (24). (7) Replace a defective valve spring (42 or 43). (8) Replace worn valve guides (49). (9) Replace    cylinder    head    (50)    with    worn contact surface. (10)   Replace  cylinder  heads  (50)  if  valve  seats can not be recut. (11)   Replace cylinder head (80) if cracked. (12)   Replace  worn  piston  rings  (10,  11,  12  and 13).  Replace rings as a set. (13)   Replace  pistons  (9)  that  have  worn  piston ring grooves beyond  the  limits  set  in  Table 6-1. (14)   Replace damaged piston (9). (15)   Replace piston pin bushing (16) that is worn beyond the limits set in Table 6-1. (16)   Replace a defective or worn connecting rod (17). (17)   Replace bearings (22a, 35 and 39) that are scored or worn beyond the limits designated in Table 6-1. (18)   Replace   oil   pump   (53)   if   shaft   is   worn. Replace  gear  wheel  (52)  if  teeth  are  worn or cracked. (19)   Replace   defective   springs   (54,   55a,   and 56),    damaged    levers    (55    and    58)    and control rod (59). (20)   Replace crankshaft (45, Figure 8-30, Sheet 4 of 10) if worn beyond permissible limits. e. Assembly.        To    assemble    the    diesel    engine assembly proceed as follows: NOTE Before o-rings (55.) are installed, the contact area should be lightly ground. (1) Figure 8-30, Sheet 9 of 10.  If stud (61) was re-moved, screw studs (61) into crankcase, install gasket (52) over stud (61).  Place o- ring  (55)  for  cooler  tubes  (54)  into  oil  pipe right (51) and oil pipe left (53).  Install the oil cooler tubes (54) into oil pipe right (51) and oil  pipe  left  (53)  and  mount  on  crankcase using  stud  (61),  washer  (35),  nut  (34)  and screws (50). (2) Install  support  (37),  cover  (36)  and  spacer (38,   39)   using   washers   (30)   and   screws (29). (3) Figure 8-30, Sheet 6 of 10.  Screw hex nut (52)   into   stud   (51),   screw   stud   (51)   into crankcase   through   oil   splash   plate   (53). Install  intermediate  plate  (50),  screen  (49), breather  plate  (48),  diaphragm  (47),  plate (46) and spring (45) over stud (51).  Install gasket (44) into  cover  (43)  and  spring  (45) over   stud   (51).      Install   gasket   (44)   into cover  (43)  and  install  cover  (43)  over  stud (51) using washer (42) and nut (41). CAUTION Oil    holes    in    bearings    must    line    up    with    holes    in crankcase during installation of any bearing. 6-45