Syn

I have a '99 A4 Trans Am that has had a clunking from the rear when I come to a stop when it downshifts back into first gear. It doesn't clunk if I brake lightly when stopping and it doesn't clunk if I put the car in neutral and brake lightly or hard. But under most normal driving situations I can feel and slightly hear a clunk from the rear during stopping. Does anybody have any ideas what this could be? Or is it 'normal' and I just need to deal with it? The car accelerates just fine and it only clunks when stopping like I described above.

P.S. I have had the rear end gear oil changed within the last 5k miles and they even put in more of the limited slip additive per someone's suggestion previously when I made a thread like this a few months back. I started noticing it when my brakes were giving me problems and was hoping it would stop when I got the brakes done, thinking it had something to do with how hard I had to press the brake pedal or something, but it's still doing it now after the brakes were done. Is there some kind of programming with the A4 that determines how 'hard' to downshift based on how hard I press the brakes? Or is it something else?

jmm98LS1

iTrader: (28)

u-joints maybe? You don't notice the noise any other times?

Pats Fan

iTrader: (3)

I have an '00 Z28 and it's been clunking like that since it was new. I had the dealer check it and he said they took out another one and it did the same thing. I haven't had any problems with the rear end aside from that noise...

Syn

I was kind of thinking this would be the case. It's really only noticeable under moderate-to-heavy braking when coming to a complete stop when it downshifts back into 1st gear. It will not do it at all if I brake lightly. For a long time there I was having to brake harder than normal because I was having brake problems and my pads were pieces of crap, but now I am back to a good set of front brakes and it is not doing it nearly as much because I don't have to use as much force on the pedal to stop the car.


I only notice it when I have my music turned down, otherwise it's not even loud enough to hear. If anybody else has opinions let me know.

RobZ28

My car has done that since I had it. It doesn't appear to be anything. I really feel/ hear it form the 2nd to first downshift. My car does have a shift kit though so that might have something to do with it.

Starion

iTrader: (5)

I notice the clunk on mine as well sometimes on hard braking. I think it's from u-joint wear personally. Whatever it is, I wouldn't worry about it too much.

If your ATF is old and causing harsher shifts you'll clunk more. New atf made a world of difference in mine and made it less clunky

Caribe

iTrader: (1)

Check all you panhard bar bolts. I had a clunk when braking. Ended up being a loose bolt on the upper panhard bar.

Robins Midnight Blue

I have a 2000 Z28, and have never heard this noise. However I had 1992 Corsica that made this clunk noise that sounded like the rear end, and it was a bad brake pedal switch - from leaving my cruise control on. I know that does not sound likely, but believe me, I thought it was my u-joint or my rear end, the clunk felt like something was going to fall out.
Anyway, the problem I am having on my Z28 is that it won't start after driving it, I have to wait for it to "cool off" 20 - 30 min. I have replaced the battery and the starter. - which seemed to have fixed the problem for about three weeks, but now I am having the same problem. After driving anywhere, I cannot start the car - it doesn't turn over, just click. Jump starting will not work, I just have to wait every time. Could this be my nutrl switch??

MavZ28

iTrader: (1)

I'm with you on this too! I just switched out my brakes too and had my rear done about 5k ago. I needed it all anyways, but I've been doing it earlier than expected hoping to diagnose this mystery noise as well.

I'm definately with you on this. I'm thinking the U-joints make sense? But I have it exactly as you described, intermittently at low speeds and seemingly after a good braking/warm up period. And its not quite loud to really worry about I've been told, but its a clunk that just doesn't sound good at all. I'll be subscribing to this thread! Hopefully someone will chime in with something. It appears that there are others (though some above don't quite seem exactly, but enough to warrant a LOOK OUT!)

waldershrek

iTrader: (1)

Climb under her and have a look. Check all your bolt on LCA's, panhard bar etc....

SpaZMaN

iTrader: (5)

that my suggestion, check all the suspension bolts and all that

MavZ28

iTrader: (1)

some suggested that perhaps a tooth off the gears may have broken off? That make sense? I thought I'd chime in with that possibility, as I won't have time to take the rear apart just to look until next weekend. Plus I just changed the darn fluid....grrrrrr!

What do you guys think?