Need help fix knocking sound

Hi, the problem I have is rather a common one - knock/clunk coming from the rear..and Im looking to fix it up. Its an '06 A4.

Ive done quite a bit of search for the solution and not sure of what I could do to fix my car at this state, because I want to get it done. I know Im not the only one with this issue. I always find the same answers..'drivetrain lash adding up through the driveline', 'the axles are loose' ect

I know what the sound is and where its coming from, just cant figure out the problem as in what to fix. And I just cant afford to throw thousands out there and say 'replace the whole thing'.

I just want to get in my car and drive it without having to deal with something falling/snapping off in the future, because I love it and already put too much work into it(not horsepower-wise) so you cant blame that. I cant just be in the 'knocking sound club' and 'ride it out' any more, its getting kinda bad:/

The usual symptoms. It happens when accelerating and its switching gears @ lower speeds. I could be smooth on the gas and not hear it, but its worse when the T/C is off. For me, I want to say its coming more from the right rear area. The right shaft seems to be a bit loose when I try to turn it, the left one doesnt move at all. Ive already tighten all that I could down there.

So is it the halfshaft I need to replace? new differential? axle stubs?

I know its a bit rediculous asking for help on a problem so many owners already have but I really dont know what else to do. A friend and I do work together on stuff like bushings, suspensions, headers, but this is a bit out of our league. Ive taken the car to 4 different shops and not one mechanic can tell me whats wrong:/ Im really not sure what to do with the car at the moment, any help is greatly appreciated.

I hate to say this, but I had all kinds of knocking and clunking until my differential finally failed. I replaced it, and 99% of that is gone.

I would not, however, simply replace it based off of my statement. That can be an expensive repair, especially if you can't do it yourself.

I would post in your regional forum and see if you can get an experienced GTO owner in your area to go for a spin with you for an opinion. It might at least help you ID whether it is "normal" or not.

Gerry

My noises were caused by the upper shock absorber bushings (they were over-tightened and destroyed by Pedders). I got new ones from GM Parts House, installed them being sure not to make them too tight and the noise was gone. It's worth a look, because that noise drove me nuts until I finally solved the problem.

Quote: Originally Posted by ShoddyHog... I hate to say this, but I had all kinds of knocking and clunking until my differential finally failed. I replaced it, and 99% of that is gone. I would not, however, simply replace it based off of my statement. That can be an expensive repair, especially if you can't do it yourself. I would post in your regional forum and see if you can get an experienced GTO owner in your area to go for a spin with you for an opinion. It might at least help you ID whether it is "normal" or not. Gerry

Gerry,
Why do you have to be the bearer of bad news... I really started hearing the clunking popping sound today. I had heard it before, but not this loud... I was coasting at about 20mph tonight and I heard it over the radio and the exhaust note (and by no means do I listen to the radio at a low level). I guess i will be putting it up on stands tomorrow and taking a look to make sure everything is tight just to rule out anything else.