Grinding noise when backing up and turning
 

I've read the threads about grinding when backing up and the brake rust. But my wifes 2SS/A6 only does it when the wheels are turned sharp.

It doesn't do it if she backs up straight. And, it doesn't do it when I'm standing outside listening. :rolleyes:

She has, on a couple of occassions heard it when turning the wheels sharply and going forward. (Like getting out of a parallel parking spot.)

She took it to the dealer and of course - they couldn't find anything wrong.

She can't tell if the "grinding" is coming from the front or rear or middle. It's just coming from under the car.

I'd believe the brake rust, but...
* It won't do it unless the wheels are turned sharply.
* It will do it even if only parked for a few minutes. (Not just when parked overnight.)

Any ideas?

Mine does this too - I would love to hear what anyone has to say about it.

As for brake rust, mine will do it after driving a hundred miles stop and go - but it will almost always do it going forward, and backwards.

Check the power steering fluid. My 1990 1500 used to do the same thing only when backing up and turning.

mine does it too on occassion but only when backing up with the wheel turned sharply. It is no big deal. My Cobra replica did it as well and for it fixed with anti moan brackets. But I will not be diong this to my camaro. What it is the rotor flexes and contacts the caliper ever so slightly and causes the "brake moan."

Think about this:
Very large tires, very little clearence in the inner wheel wells, when the frt. tires are turned sharply maybe the tires are rubbing ever so slightly on the plastic inner fenders.

I would check in these areas to see if tire rash is found could be the problem.:iono:

We've checked for tire rub, and no, there seems to be plenty of clearance.

My wife and I both purchased a 2SS A6. Mine does not do this at all. Hers is about 2200 vehicles newer than mine. Something is definately different. Rotor flex??? Could be. I know it's not brake rust, as it does it anytime, even if stopping for just a minute to run into the store.

Thanks for the ideas.

Is she holding the steering wheel against the stops. If she is it is the power steering pump trying to pump fluid but it's dead heading and has no where to pump. This eventually will ruin the pump.

No. I've been in her car when it has done it. The best description of the sound is a grinding noise. It's almost as though she does have rust on warped rotors. And, you can hear it under the car. I think it's towards the rear, she thinks it's passenger front or passenger rear.

You can hear a grind, no grind, then grind, then no grind, then grind. It's either with each wheel/drive shaft rotation, or possibly a couple of times per rotation.

The problem is, when I'm standing outside near the car to try and hear it when backing up, it never does it. (Of course.)

If she were dead heading, I'd think you would hear a constant noise while pegged against the turn limit.

Again, thanks for the ideas. It's starting to drive her crazy! I think we're both to the point that we wish it would do it all the time so we can duplicate it for the dealer.

The car has wide front tires 245's and when turning very sharp and going very slow, the front of the car may feel like it is skipping(grinding) a bit over the road and pulsating a little bit. This is normal due to the wide tires and the alignment settings. You will not hear this noise when you are outside of the car and listening. It is a vibration being amplified into the cabin from the tires. This is normal and I wouldn't be concerned.

Has your wife driven your car and heard what she heard in her car? If not get her to try it out.

245 isn't that wide, plus I doubt that would affect it at these low speeds. I also highly doubt GM would ever let the car go with the tires coming even close to rubbing on anything even when turned all the way.

I only say this because I thought that's what it was when I first heard/felt this myself in my SS. But when it happened the second, third, fourth time etc., and I felt it IN the brake pedal, I knew it was something else. I hear a noise, I wouldn't describe it as grinding really, it's hard to explain or even duplicate, but I absolutely feel it through the brake pedal. Happens at least every other day when backing out of my driveway, and when I get to work and back into a spot. So I can't say it only happens when it's cold, and it's not rust being as this has happened in summer, fall, rain, or shine. I've actually never noticed it after washing the car when there is rust on the rotors, in fact the car just seems to stop quicker when that bit of rust is there. I haven't taken it in to the dealer though, I'm just accepting it as a normal issue in the system. As long as it only does it when I'm backing up, I'm fine with that.

Oh I also have the Brembo GT kit, so new rotors and calipers. It did this before this kit was installed, and it still does it now with the kit on. Must be something elsewhere within the braking system.

-Mike

also i would change your rear diff fluid if you havent yet, mine was making a grinding/ moaning every sharp turn or when backing out of my drive way.

new gm synthetic gear lube with additive and the noise went right away

71cam - Are you kidding? Let my wife drive my car? :confused0068: Just kidding. Actually, that's a good idea. I'll have her park mine in her spot in the garage and let her back mine out a few times over the holiday break. (While I carefully watch though.)

SS Mike - You've hit the description on the head of the nail. It's not a grinding, and you can't really describe it. However, my wife says she too can "feel it in the break pedal." I finally did think I heard it the other day when standing outside. It was a cross between a low pitch squeak, with a rub, with a grind. Somewhere in there. :iono:

I suspected that maybe the Brembo brake calipers were not releasing sometimes, and that maybe it was picking up some "flex" in the rotors when turning sharp. It would explain the feel, and explain why it's not just rust. But you've changed calipers and still have the noise? Interesting.

She has also tried never engaging the emergency brake - that didn't help.

She has turned off traction control, that didn't help. She'll try turning off both traction and stabilatrack next.

Additionally, she has to parallel park almost every day at work, and when driving forward, it will do it when getting out of the spot. Other than that, it only does it in reverse.

Same thing happens to me backing out of my steep driveway only happens when trning my wheels but bad enough to say oh sh*# what was that. Now i try to keep my wheels straight when backing out

Yea it is definitely hard to explain as far as the noise and feel. But it looks like we're not alone and others have experienced this as well. Mine does it when my wheels are turned even just a little, so I can rule out rubbing. Hopefully someone will figure it out sometime.

BTW it's SS Mike, not AA Mike. AA Mike sounds like I'm on a 12 step program or somethin, don't want people to get the wrong idea ;) hahahaha :drinking: