Universal Joint Noise

If a universal joint is suspected of producing a rattling or knocking noise, the universal joint may be worn or loose. Make a preliminary inspection as follows:

1. Grasp the propeller shaft toward the end near the suspected universal joint.
2. Rotate the propeller shaft back and forth.
Fig 1: View Of Propeller Shaft & Universal Joint
Courtesy of GENERAL MOTORS CORP.
3. Move the propeller shaft (1) in an up and down direction while feeling for any looseness. If the propeller shaft (1) shows excessive movement, remove the universal joint (2) and perform the following inspection:
   • Inspect the needle bearings for locking or wear. If the needle bearings exhibit signs of locking or wear, replace the universal joint as an assembly .
   • Inspect the bearing surfaces on spiders for wear or flat spots. If the spider bearing surfaces exhibit flat spots or appear worn, replace the universal joint as an assembly.
   • Inspect the bearing caps for cracks or other damage. If the bearing caps are damaged in any way, replace the universal joint as an assembly.