Clunking, knocking--Mount??

[Silver 99 Camaro]

I have an automatic, but for a long time now I have been getting a really hard clunk/knock when I put the car from Park to Reverse. Now, sometimes when going slow in parking lots, it clunks really hard shifting from 1-2 and sometimes on the street. Now, I've had the infamous posi rear-end clunck on decels for a long, long time, and I thought it was that just getting worse. I also thought trans mount issues were mainly for the T-5's. Is it possible the mount might be bad causing some of these noises on my auto?

[Angel]

Re: Clunking, knocking--Mount??

I have an automatic, but for a long time now I have been getting a really hard clunk/knock when I put the car from Park to Reverse. Now, sometimes when going slow in parking lots, it clunks really hard shifting from 1-2 and sometimes on the street. Now, I've had the infamous posi rear-end clunck on decels for a long, long time, and I thought it was that just getting worse. I also thought trans mount issues were mainly for the T-5's. Is it possible the mount might be bad causing some of these noises on my auto?

your problem might be the torque converter if it makes that every time you trhow it into gear or your mounts... now the axles seem to be the same problem as my posi trac rear end, they sqeuak when you drive really slow... im trying to figure out where to get them or if i should just get another posi trac rear end. keep me posted

[WishIHad$$$]

Re: Clunking, knocking--Mount??

Sounds like trans mount to me. Mine went out on my old V6, A4. It's a relatively cheap fix.

[Silver 99 Camaro]

Re: Clunking, knocking--Mount??

Well I was listening to it yesterday more closely and the clunking is coming from the rear only, not the transmission hump/tunnel. So I am pretty sure it's just play in the torsen posi unit getting worse. Unless I am mistaken, and tranmission mount clunk would be up front or around the console where the transmission is located.

[Loochy88]

Re: Clunking, knocking--Mount??

sounds will carry up and down the tunnel. i would get that mount replaced for sure. get a cheap poly mount from autozone, or a replacement 1le. its an easy job and then youll be able to rule it out if it doesnt work. i had the same problem exactly, and the mount fixed it.

[3.4 slow to go]

Re: Clunking, knocking--Mount??

sounds like your u-joints are dead. either regrease them, or replace them. clunk putting it in reverse was a give it aaway for me.

[logan13883]

Re: Clunking, knocking--Mount??

Bad U-joints, requiring replacement, will produce a clunking sound wen the car is put into gear, This is due to worn needle bearings or a scored trunnion end possibly caused by improper lubrication during assembly. U-joints require no peridoic maintenance and therefore have no lubrication fittings .

Dissassembly of the U-joint requires the joint to be pressed from the yoke, This results in damage to the bearing cups and destruction on the nylon rings.
Replacement kits include new bearing cups and conventional snaprings to replace the original nylon rings.

Just a few things it says in the chilton manual, i have no idea if ita help u any , i havent yet worked on that part on my car so i really dont know ,well anyways gl

[BLLDOGG]

Re: Clunking, knocking--Mount??

if you are not sure, replace the cheapest one first. could be either. if you bring your shaft into a u-joint shop, its usually really cheap.

[shock_core]

Re: Clunking, knocking--Mount??

make sure you t/q arm bushing isn't dead. I had the same problem. Other than that, check the U joints, panhard rod ( check that its bolted down tight ). Other than that I don't really know.

[3.4 slow to go]

Re: Clunking, knocking--Mount??

I had my u-joints removed off the bird for $5. It takes a toch to heat up the plastic. really coolto watch all that crap ooze out, then beat the shiz outta the top of teh u-joint to get it to drop. jsut remember to mark which end is teh front.

[Silver 99 Camaro]

Re: Clunking, knocking--Mount??

So it sure sounds like there is definitely something wrong other than the rear end play and it is either the trans mount or the rear u-joint. It has gotten pretty annoying especially since it is clunking now while driving normally when the car shift from 1-2 and sometime 2-3.

So, how do I check to see if it is the tranmission mount or the u-joint? Any dead giveaway things to look for, or simple tests to perform to see which it is? Thanks for all the replies guys, it has been helpful.

[Silver 99 Camaro]

Re: Clunking, knocking--Mount??

I finally got around to checking everything out underneath the car. Here is what I found...

The trans mount is ok, not broken at all. It has some small spider-web like cracks around it but it's still holding on pretty well.

The torque arm bushing is toast...it's all hollowed out around the torque arm and the rubber is falling apart. Would that cause the rear end to clunk on shifts?

There also was a little play in the u-joint and tailshaft on the trans. It was very minimal, and probably expected on a car with 80K and a lot of powerbraking!

Based on what I found, any idea what the problem could be? Keep in mind the clunk is only on upshifts 1-2 and 2-3, and downshifts 2-1 coming very distinctly from the rear of the car, not the tunnel/hump. Thanks!

[Shad0wguy]

Re: Clunking, knocking--Mount??

Sorry to revive this from the dead, but where can I take my driveshaft to get the u-joint replaced? Can any old mechanic shop do it?