TM  9-2815-202-34 4-25.  IDLER  GEAR  REPLACEMENT  (Cont) e.   Installation (1) (2) (3) (4) Aline  timing  marks  on  camshaft  gear (25) and crankshaft gear (26) with timing  marks  on  idler  gear  assembly (3). Slide idler gear assembly (3) into position  until  crankshaft  gear  and camshaft gear are fully meshed. Rotate gear hub (11 ) until dowel alines with hole in end plate. Tap hub until it seats against end plate. Install bolt (1) and flat washer (2) securing  idler  gear  assembly  (3)  to cylinder  block.  Torque  bolt  to 80-90 Ib-ft (108-122 N-m). NOTE Backlash can only be checked with cylinder  head  removed, (5) Mount dial indicator on end plate and check  backlash  between  idler  gear assembly (3) and mating gears. Minimum  backlash  is  0.002  in.. Maximum backlash is 0.008 in. for new gears and 0.010 in. for used gears. NOTE Effective up to engine number 8VA- 349267,  a  dummy  hub  was  installed opposite idler gear hub to fit the original flywheel   housing. (6) Install dummy hub (6) on end plate. Install bolt (4) and flat washer (5). Torque bolt to 80-90 Ib-ft (108-122 N-m). END OF TASK FOLLOW-ON  MAINTENANCE Para   Description 4-24 Install flywheel housing 4-92