TM 10-3930-659-34 4-8. IDLER GEARS MAINTENANCE (Con’t). CAUTION To prevent loss of timing, ensure that other gears DO NOT turn when installing upper idler gear. 4. Apply lubricating oil to upper idler gear (15) and install upper idler gear on upper idler gearshaft (14). TA708084 5. Install thrustwasher (16) and bolt (17) on upper idler gear (15). Torque bolt to 65 lb.-ft. (88 N.m). 4-41 4-41