Drive/Propeller Shafts, Bearings and Joints: Testing and Inspection

- Vibrations and knocking noises are the most common complaints with propeller shafts and universal joints. Vibrations are often caused by wear, poor lubrication and incorrect installation. A humming noise which increases with speed usually confirms a vibrating propeller shaft.

- Worn universal joints usually cause knocking at low speeds and also when the accelerator pedal is depressed and released.

- Cracked or damaged propeller shafts must not be repaired or realigned. New units must be installed instead.