Squeal
06-21-2011, 01:20 PM
#1
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Join Date: Aug 2009
Posts: 173
Squeal
So I just did a whole lot of suspension work front and back, I have a few recent threads out there in this forum about it. I figured if I had any issues it would be with the front, since it's so much more complicated. The only issue I have is in the rear, there is a squeal only when doing sharp turns. In the rear I replaced the brakes (rotors and pads) shocks (bilsteins) and tires/wheels (went from stock 16" salad shooters to 17x9.5 zr1's. My first thought from the sound (cyclic squealing during sharp turns, like spinning metal hitting metal) was that the rim was rubbing on the driver side but I pulled a wheel off and couldn't see any rub/scrape marks, and from what I can see from under the car, I can't see that anything else is rubbing either. Any ideas from what I did out back that could be causing this?
06-21-2011, 07:01 PM
#3
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,834
Re: Squeal
Here's a quote from the 4th Gen FAQ..... does this sound like your problem:
http://www.ws6.com/faq/
Q: What's that metal squealing noise from the rear on high speed turns?
A: Assuming that you haven't completely run a brake pad down the metal plate, this noise can come from C-clip axle end play. This moves the rotor closer and father away from the caliper mount. When the edge of the rotor touches the caliper mount, you will hear the noise - usually only when turning in one direction (i.e. rotor moves out enough to hit in only one direction). The Caliper mount can be relieved in the area that it touches or the caliper mount can be shimmed. Keep in mind, if this was not a problem, GM would not have shims. In the 1994 service manual, information on this can be found under "Brake Caliper Alignment" in section 4B - page 27 (4B-27), entitled: "Rear axle assembly with rear disc brakes" (figures 1 through 4 and 38). There is however a Technical Service Bulletin (#474201A) for this which you should advise your GM service person about.
A: Assuming that you haven't completely run a brake pad down the metal plate, this noise can come from C-clip axle end play. This moves the rotor closer and father away from the caliper mount. When the edge of the rotor touches the caliper mount, you will hear the noise - usually only when turning in one direction (i.e. rotor moves out enough to hit in only one direction). The Caliper mount can be relieved in the area that it touches or the caliper mount can be shimmed. Keep in mind, if this was not a problem, GM would not have shims. In the 1994 service manual, information on this can be found under "Brake Caliper Alignment" in section 4B - page 27 (4B-27), entitled: "Rear axle assembly with rear disc brakes" (figures 1 through 4 and 38). There is however a Technical Service Bulletin (#474201A) for this which you should advise your GM service person about.
06-21-2011, 09:59 PM
#5
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Join Date: Apr 2008
Location: OH
Posts: 313
Re: Squeal
I could see the dimensions of your new rotors being off just enough to cause an issue. While not an F-car, I'll say that we ended up having to shave a couple thousandths off a new set of rotors for my fiance's Sebring. They squealed like hell going around turns for no apparent reason. Upon closer inspection, we found that a particular lip on the backside of the rotor was slightly thicker than the stock one, causing it to grind against the hub area on the spindle. Knocked it down on a lathe and the squeal was gone.
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