Sound from the rear

[Horst]

Hi,

when driving very slow, let´s say 15 mph or so, and when not pressing the accelarator at all, so slowly descelerating or even slightly braking, I can hear a mechanic sound from the rear. It is not loud and sounds like a "clack-clack-clack-clack" in a pace that could be connected to the revs of the rear wheels. This sound is also audible when rolling in N.

It is not audible when going faster or accelerating or going at a constant speed.

What can this be?

[Denis]

Do you have the Y87?

[Red V6 Raider]

Have you ever taken your car to the autobahn? [img]graemlins/naughty.gif[/img]

[ka50]

Lemme guess... if you press and release the accelerator at around 15mph few times it will do "clunk-clunk-clunk" when you press and release the accelerator, right? It's called driveline clunk, I have it too. In neutral I don't have it though... only when I put in gear.

[Horst]

Most of the Euoropean Camaros came with the limited slip diffeentials. With my car I´m not 100% sure, because I´ve got it second hand and someone has removed the sticker with the RPO codes. But I do know that ít has got 3.42 gears, so it is very probable that the limited slip differential is in the car.

Of course I have taken it to the Autobahn. I have do drive the Autobahn quite frequently. I like driving at a 125 mph if traffic permits, although the wind noise is getting exessive above 105 mph.

So if it is "driveline clunk": Is that a problem? Will it get worse?

[Silver 99 Camaro]

I have a similar thing going on. It also clunks when putting it in reverse and coming to a stop ( the 2-1 downshift). Last weekend I looked at it. There is no play in the differential, suspension fine, U-joint fine, transmission fine. I did find a clunk in the axles when I moved the tires up and down, telling me the axle bearings are shot. I am taking it in tomorrow. I'll repost when they tell me what it is. Hopefully this helps.

[Horst]

The more I listen to it, the less I believe it is the "driveline-clonk".

It is audible only at very defined speeds. When I drive normally and slowly brake down to standstill, then the "clack-clack-clack" is audible only at a speed between 25 and 20 mph.

As I said - only when slightly braking or descelerating, not on cruise control or accelerating, and only between 20 and 25 mph.

[Silver 99 Camaro]

Don't worry about it. I had mine checked over the weekend, and they said it was the torsen posi unit clunking around. It happens at low speeds, when slowing or getting on and off the gas. If you have a posi rear end in your 2000, it's a torsen, and it can make that noise over time. They said there is nothing they can do short of replacing the posi unit, and there is no need to if you can live with the noise. If that's your problem, it's not a big deal. You may want to get it checked just to be sure. They changed the fluid in mine and said turn the radio up louder. The chances of it actually failing are slim to none, unless you slap slicks on and beat the hell out of it. Good luck!

[Rob Bell]

So, Horst, is 125 as fast as it will go, or do you think it can go faster? I also have 3.42's in mine but of course we have the 118 MPH speed limiter here. Plus I wouldn't dare go that fast around here anyway. I got mine up to 105 once on the expressway but chickened out because there's always too much traffic.

[HiWire]

I have the same exact problem. I don't have posi so that can't be it. Im almost thinking its something to do w/ rear drum brakes. It only happens when at 20 mph or lower, like when I'm cruising for a parking space. However, when I press in the brake a little it stops. I wouldn't mind knowing what the hell it is, I've had it for like almost a year now.

[Horst]

Dear RobBell,

yes, with the limiter disabled it could go faster. It approaches the 125 fairly quickly, untill it is electronically limited at that speed.

With the given hp it should max out at about 135 mph, and as a matter of fact, that´s the top speed a European supplier of performance chips claim for their product.

I heard from other Europeans that with such a chip and a RAM Air/exhaust mod they where doing speeds in excess of 140 mph, which is about 145 on the speedo. I would have gotten such a chip already, but mine is a 2000 and I don´t know whether it would work. I know, that the US models from 2000 on where only tunable with a Hypertech programmer, but the folks at Hypertech can´t tell me whether their product will work on an export Camaro.

Dear HiWire: It can´t be the drums om my car. I´ve got disks all around.

[SilverRS96]

i had a simialr clunking noise but it ended up being my tranny mount that was shot...it might be that but who knows since your car is a 00

[Die Ford V8]

if it is your bearings cant your tire and axle from one side of your driveshaft just fall out. I watched a rachero do this. he caught it before the axle came out of the rear, but it was close. like go go gadget wheelbase or something:)

[Silver 99 Camaro]

No, the axles use c-clips that hold them to the differential. The axle bearings hold the axle in place up and down, side to side, not in and out. I doubt it's bearings. I was told that bad bearings produce a loud roaring sound that no one could miss. I honestly think it's the same problem I have and that a lot of the V-8 guys are having with their rear ends. The posi torsen unit develops play over time and clunks around. If you don't have posi then I have no idea what it is. If yours is a 98 or older is doesn't have a torsen, so that wouldn't be it either. If it was the tranny mount, the shifter would move around and you would feel it in the console area between the front seats. If it's the rear only, then I doubt it's the tranny mount. But any rear clunks in rears with posi 99 and later are most likely torsen units getting old and loose.