Been to dealer three times with this problem. Get a knocking noise from rear end/suspension on slow down (usually around 20mph with clutch engaged of disengaged) and a grinding noise when putting loads on a side (swerving left in particular). Dealer has adjusted gear backlash, changed axle bearings, etc. Still there! Rearend also seems to have a lot of whine when engine is under cruising speed load. Intermittent problem so it's very frustrating! Anyone else ever experienced this? Need to get it fixed before warranty runs out! Thanks!

 

ttt... just thought someone new may be on who's experienced this.

 

Hey Bluegreen, man i feel your pain!!! I have a 2000 TA and i have the same problem! It happens at 25 mph or below and with my foot off the gas pedal(A4) makeing a left turn 45 degrees or so, sound familiar It is still under warranty so at least the money aspect is covered. But i have been to the dealer 3 seperate times and they cant seem to find it! First they couldnt find anything wrong , then they changed my bearings, and the third time the put a brand housing in( thinking it was worped) and it still is there! So now they ordered new axles. Still waiting for them to come in and see if that is the problem. If that isnt it i dont know what the hell else it could be. If you want i will give you my dealers number so the monkeies can talk amongst eachother and come up with a plan because my monkies went as far as to calling GM and asking them if they have heard of this before because they are clueless as to what it could be. Hell at first they tried telling me it was an exhaust hanger, bunch of crooks!!!! In any case let me know what happens.

 

If your noise is a tapping or clicking on decel only it is probably in the rear axle. The carrier is a Zexel Torsen and is a worm gear posi-unit. The worm gears tend to make this noise, it is called radial gear float and Zexel says it's characteristic. No damage is being caused if this is what it is, just the nature of the beast.
The rear axle whine seems to be in most F-bodies. I haven't been in too many that you can't hear this in after several thousand miles. As long as your pattern looks good on the ring and pinion and there isn't any metal in the fluid (indicating something is coming apart), you probably are ok. Hope this helps.

 

Hey kjlvilla, its not really a clicking noise its more like a clunking noise sort of like what it would sound like if the lug nuts were loose or something. It cant be normal otherwise the dealership wouldnt be trying to fix it. But hey maybe the clunking noise will ring a bell in your memory bank because it seems like you know your ****. Thanks for input.

 

thats odd.....

 

I know a bad panhard rod bushing can make the clunking noise. Especially when turning. It sounds like you got 2 separate noises. The gears which is somewhat normal and possibly the bushing.

 

I had a ploblem with my car that sounds the same. loud clunking noise from the rear of car, dealership replaced spring and many other rear components and problem was never fixed. was getting new brakes later in the week and found it was accually the REAR HUB HAVING ONLY 2 OF THE 4 BOLTS STILL ON, AND ONE OF THEM WAS LOOSE!! to check it go under the car with a flashlight or take of the rear wheels and inspect where the hub attaches to the axel. good luck!

 

Thanks for all the input. I guess I'll head back to the dreaded dealer once more and see what they have to say.

 

I'll check around and see what I can find. The loose hub bolts rings a bell for your year. The only other thing I can think of I've seen is in the mid 90's f-bodies, I think it was the caliper to rotor clearance causing a scraping noise, most noticeable swerving and on decel, because the engine/exh noise wasn't drowning it out like on accel. It is an obscure fix, if I remember correctly, you can find a shim and part number in the rear axle section of a 94 f-body service manual. It is listed in the back of the section by the specifications for cars with rear discs. It should apply because I think the axle set-up is the same from 93 - current, but it's been a while since I messed with susp/brakes on f-bodies.
Does your noise go away with braking? Do you feel any vibration, like a ground out? Anything in the brake pedal? The dealer can try some alternate diagnostics lile removing the rear linings and line clamping the rear brake lines to see if they affect the noise. Have they removed your parking brake shoes, I think you have a drum in hat set-up where they are seperate and they can do this. If you have a worn bushing and the dealer can't find this, find another dealer. They can also loosen and retorque the panhard bars, control arms, sway bars, etc. This may resettle the rear suspension mounts. If it's a knocking on decel I doubt this is it though. I'll post a reply if/when I find something.

 

Here's the best I got. For your turning noise, check the backing plate bolts at the 4 and 7 o'clock positions. The backing plate may be flexing and contacting them. Simply pry the backing plate to make clearance. Don't pry too much. You may see witness marks on the bolt heads or backing plate confirming this.
Check for the park brake off it's retaining clip (at the 12 o'clock position).
Check for the rear brake backing plates for being loose. If so, take your car to the dealer, they have a fix for this, different bolts.
If all else fails, see it your dealer has a tool called chassis ears. They are little microphones that you can clip to different areas of the car and listen to them through a set of headphones. If you want your own set, I think Snap-on and Mac sell them. Good luck.

 

Here's the best I got. For your turning noise, check the backing plate bolts at the 4 and 7 o'clock positions. The backing plate may be flexing and contacting them. Simply pry the backing plate to make clearance. Don't pry too much. You may see witness marks on the bolt heads or backing plate confirming this.
Check for the park brake off it's retaining clip (at the 12 o'clock position).
Check for the rear brake backing plates for being loose. If so, take your car to the dealer, they have a fix for this, different bolts.
If all else fails, see it your dealer has a tool called chassis ears. They are little microphones that you can clip to different areas of the car and listen to them through a set of headphones. If you want your own set, I think Snap-on and Mac sell them. Good luck.

 

Thanks to all of you who responded! Car goes to dealer in the morning??? We'll see what happens. In the meantime I found these thread here and on the firehawk page. They have about the same description of problem so I'm beginning to wonder about fluid in rearend? Dealer is the only one who's messed with it and it made the noise before they got a hold of it. Just wanted to see what you guys thought.

Thread #1
Every once in a while when I am making a turn a loud pop comes from my rearend. Sometimes it is louder than others. It sounds like it is loose or like it hits the shield or something. I started to notice this at about 6500 miles after I took it to the track for the SLP customer appreciation race day. My rearend use to whine a little when I first got it, then it went away, which I heard was normal for breakin. Then at every turn in made a groaning noise, which was the limited slip fluid leaching out, fixed that problem. Now this!! Any help would be appreciated. Because my dealership has NO idea about these cars and the last time I had to find out how to solve the problem for them here online.

Thread #2
I've noticed a popping or cliunking noise from my rearend when I take left turns. It's not turns under acceleration, it's only when coasting slowly around a turn that I notice it. anyone have this happen to them, or know what it could be?

Did you just recently have your rear end serviced? If so, they may not have put the limited slip additive back. With out this additive the rear has been known to creek, crack, and sound like it is coming apart when going around corners