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-   -   Rear Rubbing/Deep Pitch Noise over 65mph (no wheel play) (https://www.gmforum.com/1992-1999-91/rear-rubbing-deep-pitch-noise-over-65mph-no-wheel-play-254464/)

marquette97 Mar 27, 2007 09:09 PM

Rear Rubbing/Deep Pitch Noise over 65mph (no wheel play)
 
Over speeds of 65mph give or take a little, there is the deep deep rubbing/hum sounds coming from the rear. I thought it must be bearing, so I jacked the car up, and no play in either wheels, side to side, top to bottom. My ABS works fine.

I spun both wheels. The DR side spun smoothly and quietly. The PASS side spun smoothly and freely as well, but I also heard some slight mechanical noise, but again, no play in it.

(Idk if this is even relevant, but when making sharp, quick turns, I hear a metal clanging/knocking sound from underneath.)

Pretty soon I am going to be doing a LOT of long distance driving, and I don't want anything dangerous happening like a wheel falling off or whatever.

Wheel bearing? Serious problem or let it go for now?

bonnie94ssei Mar 27, 2007 09:56 PM

A humming noise typically describes a bearing. But a bearing will change pitch with speed. And it would be apparent even at low speeds. It would be deeper at lower speeds too. Does the sound get higher in pitch as you accelerate?

The knocking sounds (are these only in the back?) you hear could be struts/mounts. At 164K if they are original they could be an issue. Something sounds like it is loose. It could be a number of suspension parts besides the struts.

BillBoost37 Mar 28, 2007 06:44 AM

I can't agree more Bonne94.

Get back under and find something loose/broken. Check all suspension and sway bar contact points for any visual signs.

marquette97 Mar 28, 2007 12:28 PM


Does the sound get higher in pitch as you accelerate?
No It seems to stay about the same.



The knocking sounds (are these only in the back?) you hear could be struts/mounts
Yes, the sound often comes fromt he back. It may be that the heat shield over the muffler is a bit loose, idk. Just sounds like metal is shifting directly beneath the car, but nothign feels loose when I got under there last night.

bonnie94ssei Mar 28, 2007 01:15 PM

I had some loud knocking and clunking coming from the rear of my car. When I first noticed it, it was only while turning onto uneven pavement and hitting sharp bumps. It got MUCH louder a couple months ago.

Oddly enough, I was under the car one day fixing my heat shield over the muffler since it was rattling, and I noticed that one bracket on my rear sway bar rotted off of the frame. This was the cause of the loud knocking while turning the car. It has been fixed recently and the rear is quiet now.

Now, I doubt there's a lot of Bonnes around with sway bar brackets rotted off the frame, but it's something to check (especially in snowy states like Michigan and the northeast). When you turn the car, the body shifts from side to side, and something related to your sway bar and/or endlinks could be the issue since you say it happens while turning.

Next issue:

Is your humming noise something that happened recently? If so it may be a bad bearing in its early stages. My front bearing hummed fairly quiet and at certain speeds for the first day or two, then got dramatically worse and it was more evident that it was the bearing that had gone bad.

marquette97 Mar 28, 2007 02:36 PM


Is your humming noise something that happened recently? If so it may be a bad bearing in its early stages. My front bearing hummed fairly quiet and at certain speeds for the first day or two, then got dramatically worse and it was more evident that it was the bearing that had gone bad.
Nope, it's always done it (well since last year). It seems like the longer you've been driving it, the less speed it takes for the noise to appear (the lowest about 55mph). it's kind of off and on. It's pretty annoying after awhile too, because it's a deep pitched noise.


As for the banging, the sway bar mounts are fairly rusty and the bushings have deteriorated somewhat due to out awful winter roads.

bonnie94ssei Mar 28, 2007 08:31 PM

Regarding the humming noise, have you ever tried rotating tires to see if the noise goes away?

As long as your swaybar mounts are still attached to the frame you're good there. lol Your endlinks could benefit from being replaced with polyurethane endlinks (Energy Suspension or Moog), but as far as those being the cause of the noise it's not for sure. Are your struts/mounts original?

marquette97 Mar 28, 2007 10:06 PM


Regarding the humming noise, have you ever tried rotating tires to see if the noise goes away?
Yeas, they have been balanced and rotated twice in the past 8 months (because of vibration issues).

The clunking isn't that big of a deal to me, the car is so rusty underneath anyways haha. The rubbing noise is my only major concern.

Archon Mar 29, 2007 01:12 AM

Have you pulled the brake drums to check the condition of the pads, and springs?

TrueWildMan Mar 29, 2007 11:01 AM

One thing that sounds like may be happening here, is the rear of the car will squat a bit at higher speeds. Is there anything under/in the wheel-well that might be rubbing the tire at the higher speeds? Would have to be within an inch of the tire.

Are your tires/rims stock size?

Is the rubbing sounds more metal, or rubber? If more metal, might check to see if there's anything near the drums that would rub when the car squats (i.e. anything that doesn't move with the wheel as strut mount/knuckles would).


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