2004 Pontiac Grand Prix Severe Vibration

CSBREW

MEMBER
2004 PONTIAC GRAND PRIX
6 CYL
FWD
AUTOMATIC
96,000 MILES

I bought new all season tires in July for my 04 Pontiac Grand Prix GTP. At the same time had my rear wheel bearings replaced. There was a constant severe vibration after this most noticeably in the driver’s seat. I had the tires balanced 3 times. I was told I may have a damaged rim. I waited 3 months and bought new snow tires and new steel rims. The vibration continued. I had the snow tires balanced a second time and eventually had both rear wheel bearings replaced a second time (under warranty). Unfortunately the vibration is still there. It is at its worst around 100km (60mph) but is also noticeable at lower speeds.
Any ideas? Thanks in advance.

1 Reply

MMPRINCE4000

MECHANIC
8,548 POSTS

Rear bearings are a hub assy. They should have checked the rear control arms, bushings, trailing arms and bushings.
They should also inspect the knuckle for wear. They should also inspect the rear housing to make sure the mounting bolts are intact and not loose or broken.

You can jack up the rear of the car, put on stands, grasp tire then pull/push both horizontally and vertically. There should be no play, if there is, the you should be able to see it by having a friend push/pull on the tire while you look under car at components (bushings, control arms, bearings).

It is also possible they lifted the car using the control arm and bent it, when they installed the tires.