That is typically the result of worn spots in an inner cv joint housing. That wear can easily be WAY too little to feel so it can be overlooked when they rebuild a half shaft. You will also often get that wobble when installing a used half shaft. That wear occurred on the old car the shaft came from but it would have gone unnoticed until something caused the rollers to run back and forth in a slightly different area. That means shifting the engine / transmission to one side a little by adjusting the engine mounts, or when putting the shaft into a different car. The binding is caused by the torque on the shaft during acceleration, and that makes it hard for the rollers to move freely over the raised spots in the housing. Instead of freely changing length three times per wheel revolution, the shaft pushes and pulls on the spindle which tugs on the lower control arm and its rubber bushings. That movement pushes and pulls on the steering linkage and steering wheel. It will also tug back and forth on the engine.
The only way to verify the worn housing is to take it apart, clean all the grease from the six polished surfaces, then shine a light in and look for slight waves in the reflection, just like you do when looking at a car's bodywork reflecting the ground at a car show.
Saturday, April 13th, 2013 AT 3:02 AM