Rear axle wind-up may cause launch shudder even when all of the working angles are within specifications. Rear axle wind-up occurs when heavy torque during acceleration causes the pinion nose to point upward. In order to compensate for axle wind-up, the transmission output shaft can be raised slightly. Perform a road test after each shim to determine the affects on the vibration concern. Add shims until the road test indicates that the shudder is eliminated.

Transmission Shims

If a transmission requires shims, order the shims through the parts distribution system.

Installing most shims will change the transmission angle approximately 1/2 degree.

When shimming transmissions, use a shim made from steel stock at the necessary thickness. Ensure that the shim contacts the full width of the area to be shimmed. Do not use washers.