Knocking sound

Hey I have a 98 z28 M6, when im going really slow around a corner say 0-20mph sometimes i hear a knocking sound coming from the back of the car. Is this normal?

i get it too i have a 2001 m6

It is your posi. It is either a) taking a ****, or b) needs a fluid change. My car just needed a fluid change. It doesnt matter that your car is an ls1, it is the same rear end. Just change the fluid and add the limited slip additive.

Ok, i have that too, I was wondering what the heck it was... I don't know anything about my car yet.. what is POSI? how do I take care of that problem?

I have a 2002 A4 and mine does the same thing. I have been hearing it almost as long as I had the car. I will be getting the fluid change as soon as possible to see if that knocks it out.

2K2-Z28...i have an A4 also..and was wondering if yours has done the same thing my'n has done...sometimes..lets say i'm in the neighborhood..and i'm doin about 20 MPH or so..and i take my foot off the gas..and than barely touch it..i'll hear a clunk comin from the rear..it almost sounds as if something is bouncing up and hittin the undercarriage...but what stumps me is that everytime it happens..it feels like there's a slight hesitation before the clunk...does yours do this?? does anyone know what could be wrong, or causing it? thanks for any help...its starting to really get on my nerves...PS..it only does it occasionally..not everytime i back off, than get back on it.

Gentleman it sounds like what you guys are experiencing is normal, When the tires experience a differential in rotation speed the clutches inside the posi unit get pulled apart, that is the noise your hearing. For some reason it gets louder as the differential heats up, mine makes the most noise when i'm at the drag strip and i go to get on the return road.

Noslowcamaro your sound is different, it sounds like slop in the drivetrain, most cars have it but it shouldn't be very loud. If it is start checking your u joints, tranny mounts, it could even be pinion lash but thats the extreme.

Good luck and feel free to ask me any ques. Mike

SO the klunking sound is normal then? it only happens or i only notice it at low speeds. like said before, approaching my house, around residential areas.. where I am going slow.... (i don't go slow anywhere else!! ;) )

Originally posted by coletrickle350
Gentleman it sounds like what you guys are experiencing is normal, When the tires experience a differential in rotation speed the clutches inside the posi unit get pulled apart, that is the noise your hearing. For some reason it gets louder as the differential heats up, mine makes the most noise when i'm at the drag strip and i go to get on the return road.

Noslowcamaro your sound is different, it sounds like slop in the drivetrain, most cars have it but it shouldn't be very loud. If it is start checking your u joints, tranny mounts, it could even be pinion lash but thats the extreme.

Good luck and feel free to ask me any ques. Mike

You are right. The same thing was happening to me, it happened to be my tranny mount. Easy to check, easy to install, and very inexpensive...:D

same here buddy, actually i agree with checkenscreamer, reason is, i changed the fluid and it started, so i believe next time i its due i'll ask them to put the right fluid.

sit relax and drive, your car is fine :cool: