Need some help here, unidentified ticking/clicking noise
 

I just got this very nice 2000 A4 Quattro Avant, 1.8l t, auto, and have no problems except a ticking noise coming from under transmission tunnel.

It sounds like a chain hoist in operation if you can hear that. It's a semi metallic clicking that increases with speed. It does not click constantly and only at lower speeds. It is not noticeable at highway speed.

It is not engine related or at least it does not make the noise unless the vehicle is in motion. It does not seem to impair the function of the vehicle. I have put about 1000 miles on it since purchasing it and it runs fine, plenty of power.

I put it up on 4 jack stands and slid under and grabbed the drive shaft at the end of the transmission and I can move it 10 or 15 degrees by hand. Seems sloppy to me. Is there a spec for tail shaft play?

It doesn't sound like a heat shield. All the axle boots are good there is no slop in the wheels moving them by hand.

I've searched the forums for a similar problem and had no luck.

Any help or ideas would be appreciated. I ran the VAG and no codes present.

I think it may be the center carrier bearing on the drive shaft. Does that sound like a good starting point? I can move the drive shaft easily there in all directions. Seems loose.

Sounds like a good starting point.

Okay. I jacked it up and had all 4 wheels off the ground on jack stands. I pulled the heat shield to expose the drive shaft. The universal joint looks good and the carrier bearing does not look like it as failed. Not sure how I can tell that but it looks uniform. I can move the shaft in the bearing but it's not loose.

Anyway, I put the heat shield back on and dropped the car down.

Got in a took a drive and the noise is gone. Totally. It's been 3 days now and the noise has not returned.

I think I'll leave it alone for now.

Maybe it was hitting the shield. I thought you said that you could move the driveshaft in all directions.

I can move it around in a circle inside of the carrier bearing. I'm not sure how much or how far it's supposed to move but it didn't appear to be missing any of the rubber bushing that is in there.

I guess I'm going to wait until it fails. From all the posts I have read on propeller shaft failure it does not seem like a catastrophic failure is something that happens.

We'll see.

I have checked out the parts from Blau,$350 or so and a new drive shaft from 034 motorsports, $450. I think a whole new, rebuilt, drive shaft is the way to go. Seems like the OEM is not repairable without considerable effort.

Other than that I just love this little A4. I sold an A6 Quattro Avant and had to have another. Pretty zippy for a 4 banger.

rear end clicking noise
 

So the clicking noise comes and goes but nothing regular ut today it started to vibrate while also clicking. Pretty good vibration or at least pretty regular.

Ordered a new center drive shaft and we'll see if that fixes the problem.

Center drive shaft/propeller shaft
 

I got the new/rebuilt drive shaft installed and it solved the clicking and vibration problems. Not too difficult if you don't mind really greasy work.

If anyone needs help just post and I'll see what I can do. Pretty straight forward. Six bolts at each end and two in the middle. I did not have to remove the exhaust pipe. Just wiggle the shaft around it and drop it down.

Sometimes people report a problem, ask for help, and then don't provide details when the issue is resolved.

I just wanted to say that I appreciate your follow-up reports.

Follow-up reports
 

I agree 100%. I read the posts and follow some of them but when the OP doesn't report the results it sort of leaves me hanging.

I guess OPs are so dang happy that they get the problems fixed they forget all about those of us waiting for the last chapter.:p