Driveshaft support bearing fix using 3M Windo Weld

[durfA4]

This is a quick and dirty way to reinforce the flimsy center bushing that holds the rear drive shaft in place. over time this rubber bushing deteriorates and cracks causing a solid vibration in the center of the car. There are a couple ways to fix it.

1st-Audi Way. replace driveshaft for $1500 + labor
2. replace just the center bearing by pulling apart the driveshaft $130 plus lots of labor to remove driveshaft and disassemble the the center joint to replace bearing.
3. My way. it is cheap, and easy, and should work but if you have to buy a new driveshaft thats your call. I did this on my allroad but the concept applies to most other types of soft rubber mounts where a little added stiffness is required. It may work on your car but do not hold me accountable for any damages to you, your car, garage floor...

First off the driveshaft is a two piece design

and the bearing is in the center hence the name, but the bearing doesnot go bad the rubber support for the bearing deteriorates and looks like this

so I used an old trick from my days with DSMs and it was to fill the old mount with 3M Windo Weld

this is a single part urethane that is used to hold windshields in place and dries to make a firm durable rubber bushing yet will still flex.
so you will need this

1 tube windo weld
1 good chaulk gun
acetone
disposable gloves, vinyl or nitrile preferable
10mm wrench or socket
paper towels
head mounted flashlight

then jack up car using a safe method, I used a ramp under the rear tire.
get a look at your bearing

now you know where it is you have to remove the heat shield, 4 10mm nuts hold on the heat shield, once off slide it out from above the exhaust and set aside.
no you can get a good look at it.

now for the messy part, get your gloves and keep them handy, I used about 8 sets
open thew windo weld and cut the tip to flow nice
apply the windo weld directly into the void in the bearing

you will need to smooth out the the windo weld with your finger and make sure that the upper part of the mount is evenly covered. work both sides until you have even coverage.
The thicker you put it on, the stiffer the bushing will be. I just made sure at it was even all the way around,
and then moved the driveshaft around to ensure that the windoweld had a good bond.


the acetone is for clean up, make sure you get any off the exhaust. it would smell real bad when it burns off.

replace heat shield and let cure 4+ hours preferably overnight.


thats it

[FrankA6]

I ordered the 034 center bearing, but did this window weld help? did it smooth out the ride?

[redneck truck]

This is an excellent idea!! I wonder - with the right gun, you could theoretically shoot the same stuff into the fluid-filled or hollow voids in bushings and stiffen them up as well. Any idea of the approximate durometer of this stuff? In other words, supposing one tried to pour a new bushing with this stuff, would it be harder or softer than the original rubber, and more or less able to twist and articulate without cracking?

[durfA4]

For the $20 and and an hour of labor if it doesnt help your vibration your not out much. I had a bad cv shaft so most of my vibration was solved when I replaced that but, this should be the final cure. I will update torromow after it fully cures.

[audifirst]

it will be a temporary solution , I have done similar repair to my Ex-A4 driveshaft, had vibration coming from center bearing, at the end I replaced with new bearing , the weld is not strong enough it will crack again it might not crack in the same spot but will crack in another place the rubber support is brittle at this point over years it dried out and it will get worse

[redneck truck]

Sounds like the permanent solution is to set the loop and the bearing up in a jig, gouge all the rubber out, and pour a new bushing in.

[durfA4]

the 034 bearing says not for allroad, so in lieu of removing everything this seems to a simple fix. The fix on a sounds like a great idea, but also a lot of work

[boosted_A6]

The only problem with the 034 bearing is, finding someone thats willing to seperate your driveshaft(PITA) and in the prosess not bend or damage the shaft. Then you have to have it rebalanced unless you wanna take the chance that it will still be balanced when reinstalled.

[audifirst]

How is it holding up ?

[toledogt]

Hi

It's the first time in this forum so hello everybody. I'm from Barcelona, Spain.

I would ask you about the result of this fix. Is it work correctly?

Thanks to all.

[durfA4]

I haven't had an issue since I did this a year ago. It also got rid of a driveline thump under acceleration.

I also had a bad front CV shaft, that caused most of the vibrations, but I believe this helped prolong the life of the center bearing and solidify the driveline.

[toledogt]

I haven't had an issue since I did this a year ago. It also got rid of a driveline thump under acceleration.

I also had a bad front CV shaft, that caused most of the vibrations, but I believe this helped prolong the life of the center bearing and solidify the driveline.

Ok! Thanks for your answer. So, Did you have vibration because a damage in center support bearing only or in front CV shaft too... or both?...

I have vibrations in my allroad 2.7t tiptronic 2001 at 80 km/h onwards because the center support bearing has rubber too smooth and isn't strong enough to work correctly, and I want to fix it by the same way that you.

Did you finally replace full drivesfaht or CV shaft only? In Spain yo have to buy the full driveshaft because there are no exploded of the driveshaft and it's very very expenxsive (about 1200 or 1500 euros!) so, I want to try to fix it fisrt!

Thanks for your answers...

P.D: My english isn't still very good (I'm actually learning it!), but I hope you can understand me as best as you can!!..jajaja...

Regards from Barcelona!