M/T - Reassembly Precaution Output Shaft & Pump Assembly

85-48
7B
MAR., 1985
Subject: ALIGNMENT OF OVERDRIVE OUTPUT SHAFT AND PUMP ASSEMBLY WITH CASE BUSHING - DOUG NASH MANUAL TRANSMISSION WITH AUTOMATIC OVERDRIVE
Model and Year: 1984-85 CORVETTE
TO: ALL CHEVROLET DEALERS
When assembling the Doug Nash transmission overdrive unit following major repair (1984-85 Corvette Shop Manual - Section 7B), proper alignment of the output shaft and pump assembly with the case bushing is necessary to prevent possible premature bushing wear. A worn bushing may cause an oil seal leak and/or driveline vibration condition.

To ensure proper alignment of the output shaft with the pump assembly, Step 8 (1984 Shop Manual) and Step 9 (1984 Shop Manual) of OUTPUT SHAFT ASSEMBLY PROCEDURE (7B32) should be performed as follows:

^ Place pump cover on housing. Align four (4) bolt holes in cover to pump housing and install bolts finger tight. Rotate output shaft several times to align. Alternately torque bolts to 13-16 N-m (10-12 ft.lbs.).

To ensure proper alignment of assembled output shaft and pump assembly with case housing's bushing, the slip yoke portion of vehicle's propeller shaft should be used as an alignment aide while performing Step 4 of overdrive unit assembly procedure (7B-33) as follows:

^ With "O" rinqs positioned properly on pump cover, attach output shaft and pump assembly to case housing by loosely installing four (4) pump retaining bolts.

^ Rotate case housing to horizontal position and insert splined slip yoke of propeller shaft onto transmission's output shaft.

^ Alternately tighten four (4) pump retaining bolts to obtain proper alignment between slip yoke and case housing bushing. Torque bolts to 8-10 N-m (6-8 ft.lbs.).
^ Rotate output shaft several times to verify proper alignment prior to removing slip yoke and continuing with the unit assembly. If output shaft does not rotate freely, loosen four (4) pump retaining bolts and retorque to 8-10 N-m (6-8 ft.lbs.).