Mborras1

Hello all

Im in the process of replacing the center support bearing and rubber mount on my 02 A6 Quattro I have some vibration and seen the rubber is still intact but very worn and easy to move. Anyhow I dropped the shaft but between the bolt and cv yolk there is not enough room I barley got it cracked loose by cannot turn anymore. I seen a few utube vids and they all have about an inch or more to work with vs mine is about a 1/4 inch anything else I’m missing?
move been through 3 17 inch box wrenches already.
Any help or suggestions would be great thanks

2.7bt Fan

I had the same issue with my S6 but when you lift the middle of the driveshaft, where the bearing is, a small gap will open up between the bolt and the yoke, on one side of the head of the bolt, I was able to stack a few washers that I held together with a wire in that gap then when you push the middle of the driveshaft down the bolt will be pushed out, just keep on repeating this and you will be able to separate the driveshaft. I was able to get a 17mm closed end wrench on the bolt after grinding it down quite a bit. The replacement support had bought came with the wrong bearing in it, so I got the correct bearing with the same dimensions as the one I removed from "123bearing.com"

Mborras1

I got it done see pics had to grind done another 17 since the torque was already broken it was pretty Easy to spin off and pry the bolt down creating more space. This worked out great.
after everything reassemble I still have the vibration but it’s not as pronounced but can still feel the vibration from a dead stop. What else could this be? The vibration is coming from below the gear shifter. I had a friend floor it a few times from a dead stop while I sat in the back hands on the wheel well hump and all the vibration is there. New baring felt good went on solid and felt free. I marked everything prior to removing. What could be the cause?

georgeb944

The driveshaft needs to be exactly straight between the front output flange and the rear diff input flange. Audi specifies a tool to do this. When I replaced my driveshaft many years ago (I was not able to remove the bolt to replace the bearing and support) I used a laser lever device to cast a line between the front and rear flanges, and adjusted the bearing support until it all was perfectly straight. That covered the lateral adjustment. The vertical adjustment is more difficult to measure, but I had noted the size of the washers and put them back in the same position. No vibration, no knocking under acceleration.

Mborras1

Thanks, I did note there was two washers about 1/8 thick that were mounted with the support bearing. Some corrosion between the body and washer points you think that may cause the vibration? By eyeing the shaft it looked straight but the laser light makes sense to get a true reading.

il try next weekend to see what is off with a laser to get a better look.

AudiAllTheWay

Inspect the front suspension control arm bushings and ball joints for play. I had a C5 that did exactly the same thing even after replacing the center bearing which helped a bit, but it turned out to be a combined oscillation that would occur during acceleration from a stand still due to worn front upper control arms.

Mborras1

Ok give that a look this weekend didn’t even suspect the front since all the vibration is in the rear center.
thanks for the input I’ll post back with any findings.

AudiAllTheWay

Likely stating the obvious but during driveshaft installation, I would recommend to add some CV Joint grease to both end joints and be sure the end joints mating rubber gaskets are intact and in correct position. The gaskets are important and like to get hung up and wiggle around during driveshaft install. A break in the gasket or a missing gasket will cause an end joint to fail early as the liquid lubricant in the grease will eventually be ejected by centrifugal force and the joint will go dry, especially on a highway car.

Mborras1

Man thanks for that I found what seemed to be a gasket but figured it was a bunch of dried up grease I did repack with fresh grease on both ends but did not replace the gasket in fact it was in so many pcs I figured it was caked up grease. I’m guessing the shaft will need to Come back down FML.

AudiAllTheWay

In a pinch on a Sunday with no access to parts, I made one from a sheet of cork and it’s still going after 100,000KM’s.
If the gasket is not sealing then there will be a worsening line of CV Joint grease spray on the chassis area directly in line with the rotation of the gasket joint.

Stock gasket looks like this