Who here gets vibration in the rear of the car?

[FrankA6]

.............Anyone else?

Its been like this for years now.

List of parts that have been changed in the rear.

Koni Yellows and H&R Sport springs, brand new
Hotchkis sways with new end links
OEM RS6 wheels that are perfect
New Pzeros that are perfect and road forced balanced
No spacers
New rotors and pads
New wheel bearings
Both rear axles have been changed

So, for the past 2-3 years I have always had a vibration from 60ish to 75 in the rear and its worse when the car is coasting down the highway

Has anyone had this problem then fixed it?

I'm thinking the last thing to change is Center driveshaft or diff, or is there some type of shaft or diff bearing that can cause this if its bad?

[Michael B]

Same exact thing with my allraod. I have felt it since the day I bought it. I have tried new wheels and tires with road force balance. I just drove the car yesterday around 150 miles and after 65-70 it gets a horrible vibration I can feel in my seat. The steering heel does not shake one bit. I assume it has something to do with the drive shaft or motor mount/ trans mount issues. My shifter shakes alot too, but I assume that is because of worn mounts.

[FrankA6]

Same exact thing with my allraod. I have felt it since the day I bought it. I have tried new wheels and tires with road force balance. I just drove the car yesterday around 150 miles and after 65-70 it gets a horrible vibration I can feel in my seat. The steering heel does not shake one bit. I assume it has something to do with the drive shaft or motor mount/ trans mount issues. My shifter shakes alot too, but I assume that is because of worn mounts.

But I have brand new snub , trans and motor mounts (034 street dens) and it still does it.

[btsline04]

Have you checked the control arms/tie rods? Maybe they are worn or bent. Just a thought.

[Gumby]

I would at the very least pull the driveshaft cover, and check the center support bearing for play.

[FrankA6]

I would at the very least pull the driveshaft cover, and check the center support bearing for play.

Yeah I wanted to do that next, are they hard to change?

[Siricospeed]

It is most likely the center support bearing that has sagged in the rubber mount, causing an alignment issue. We have seen this happen in many cars with a 2 piece driveshaft. Pull the shields, and if the driveshaft is not concentric with the support housing, it has sagged, and will require replacement. Be sure to correctly reassemble the 2 halves of the driveshaft so that they remain balanced and aligned.