My brother has been having this problem for a while. It doesn't affect drivablilty at all but it's annoying.

Whenever you're stopped and put the car in 1st or you are shifting into 2nd at about 2-2,700K there's a clunk that sounds like it's coming form the rear. It sounds like someone is hitting the back, underside of the car with a 2x4. It's not overly loud, but I notice it. Anyway, it was taken to the dealer and we got it done under warrenty. I thought it could have been excessive pinion play and I believe,(I don't remember exactly, it was done almost a year ago) that they changed the carrier bearing.

Whatever they did the noise is still there. Any ideas on what it could be? It's an 01 SS M6 BTW.

Thanks.

 

bad u joints, check for loose or broken suspension parts , unlikey buit check the tranny mount , im a little tired and dont wanna think but try those for now lol

 

my bet would be:

torque arm mount
tranny mount
loose LCA bolt

 

Thanks guys. I'll check those out.

 

Did you just add some mods that you are making more horsepower? I know this may sound dumb, but after I put in a used performance tranny with shift kit stage 3, it then mysteriously started doing the clunk from the rear. I have since had to change the transmission mount. It also seems the side on the top of the torque arm has a little bend. Funny thing is the clunk comes and goes. After I replaced the trans mount and checked/tighted the torque arm bolts I went after the rear shocks. I switched the shocks and at the same time I noticed the bushing on the rod that goes through the trunk hole was not seated well. This correction took the clunk away for a few days, then the clunk resumed. For me it is for about 1 second I hear the clunk just or after scond gear is engaged. The clunk sounds as if its coming from just under the rear seats.

Well, the other day I was about to take it in to the mechanic shop and before I did, I had to run some errands and noticed after awhile of driving the clunking went away - hopfully doesn't come back. I take corners fast and have "stock" panhard rod, rear lower control arm and torque arm. All these help "align" the rear end, which as 'teke' mentioned it could be one of these that is cause of the problem, maybe a worn out bushing or bent arms, or rod. Bushing alone -im assuming- can have ill effects on aligning the rear end. I have since ordered polyurethane bushing for both the panhard rod and the lower control arms before going with aftermarket parts -saves me money for now.

 

LCA = lower control arm, right? Where is it located?

Everytime I put my car in reverse, or put it in park while on a hill and let off the brake pedal without engaging the parking brake, I hear a "tink-tink" sound like something's loose underneath. Do you think it could be any of the above you mentioned?

 

Take the rear wheels off and you will see a lower bar it is this one. It is U-shaped but turned upside down, aftermarket lca are boxed or tubalor.

 

The car is pretty much bone stock with only 25K on it. The reason why I think it's coming from the actual rear is because the clunk happens when the car is stopped. There is no suspension action when this happens, nothing is moving. I've chased many suspension clunks in my other car when going over bumps, this isn't a similar sound.

 

maybe the rear springs.

 

Spare tire loose?

 

I had a clunking LCA and PHB. They would only make noise when going over bumps.

 

Shock nut, LCA bolts, torque arm (on rear end), or u joints

 

Would a slip yolk do that also..??