hey guys, i am over here from the B6 A4 world... just sold my A4, looking to get into a B5 S4, and i found one... only problem is, the owner tells me the car needs a "center differential bushing" because it rattles under load in 1st and 2nd if you punch it, but if not driving it hard, nothing happens.
does this sound right? if not, what do you think i am looking at here?
i am handy with a wrench, and not afraid to DIY, but i am not as familiar with the B5 chassis. any help is greatly appreciated!

Jordon

 

Sounds like a drive shaft to me...I would have a mechanic check it out, and then use that as a bargaining chip when you negotiate the price.

 

I would hoist the S4 and inspect the drivetrain. It could be anything from the front to rear driveshaft center bushing to rear diff mounts and even rear suspension components, etc.

IIRC there was a BMW center bearing that fits the B5 driveshaft perfectly. If your issue does turn out to be a worn center bearing, you may want to check this option out further because Audi only sells the complete driveshaft that includes the center bearing and it's expen$ive.

 

Thanks for the tips guys.... It sounds like a rattle right under the armrest- I think it is the center driveshaft bearing. I know that 034 motorsports sells replacements... I will take a closer look soon.

 

How did you make out with resolving this? Simply to note, it is very difficult to properly diagnose this type of issue from listening inside the cabin. The vehicle needs to be hoisted and inspected to know for sure what is causing this issue.

 

Driveshaft support bearing

 

How did the replacement go for you?