Mechanics

PONTIAC GRAND PRIX ENGINE PROBLEM

2000 Pontiac Grand Prix • 100,000 miles

Front driverside shakes bad when accelerating stops when let off gas replaced wheel bearing and cv axel balanced tires looks like cv axel wobbles at trans never had this problem help please
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Tomgerhart
April 10, 2013.



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.

Caradiodoc
Apr 13, 2013.
I have the same problem with a honda accord and everything you say makes since but I changed the transmission which also allowed the cv joint to be rubbing in a different spot right? The transmission mounts had to come off and when I put the new one in it had to have moved slightly now when I drive and my left side pulls the tranny and the motor move back and forth causing my car to shake. So should I just put a new cv axle in would eliminate the shake? The boot and everything is busted around the joint housing has been for years.

Tiny
Mkbartram22
Apr 14, 2013.
Besides keeping dirt and water out the boot is designed to constantly push the grease back into the bearings. With the boot missing the grease is going to fling out and the joint will turn into junk real quickly. The least expensive route is to replace the entire half shaft with a rebuilt one.

Caradiodoc
Apr 14, 2013.