TM 10-3930-659-34 4-8. IDLER GEARS MAINTENANCE (Con’t). 10. Pry upper idler gear (15) away from cylinder block front plate (1) as far as possible. 11. Using  dial  indicator,  measure  and  note  end  play  of  upper  idler  gear  (15).  End  play  must  be  0.0010-0.0080  in. (0.0254-0.2032 mm). 12. Remove bolt (17) and thrustwasher (16) from upper idler gear (15). CAUTION To prevent loss of timing, ensure that other gears DO NOT turn when removing upper idler gear. 13. Remove upper idler gear (15) from upper idler gearshaft (14). NOTE Perform steps 14 and 15 only if upper idler gearshaft is damaged. 14. Remove upper idler gearshaft (14) from cylinder block front plate (1). 15. Remove thrustwasher (13) from upper idler gearshaft (14) and springpin (18). 4-38