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cant figure out WHY rear squeal

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Old Dec 6, 2009 | 02:12 PM
  #1  
chevyboy07 91's Avatar
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From: down by the river
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Last edited by chevyboy07 91; May 1, 2014 at 03:10 AM. Reason: .
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Old Dec 6, 2009 | 03:03 PM
  #2  
89RS_82Z's Avatar
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From: Fairhope, AL
Car: 89RS(other cars & pics in vBgarage)
Engine: LO3, 305 TBI Mildly Modified
Transmission: BakerBuilt 700R4 w/B&M Megashifter
Axle/Gears: 3.23 Auburn Pro Series LSD
Re: cant figure out WHY rear squeal

if the bracket is touching the rotor take the bracket off and grind off some meat from it to make a gap, but im a little lost on if that is whats causing the problem from your discription
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Old Dec 8, 2009 | 10:19 PM
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ebmiller88's Avatar
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From: Fort Mill, SC, USA
Car: '88 Iroc, '91 RS, and a '70 RS
Engine: 5.7 TPI; 5.0 TBI; ZZ4/T56 on the ag
Transmission: A4, A4, slated to be a T56
Re: cant figure out WHY rear squeal

Upon inspection I noticed that the squealing is actually coming from the caliper BRACKET in contact with the rotor (on the side closest to the rim) There is like NO clearance between the two.
No offense but don't grind on good parts.

You need to space the caliper abutment OUT toward the wheel. Stick a 7/16" flat washer in between the abutment and the backing plate, Lowe's has ones that are perfect for the job.

The axle has a bit of slack in it and this is why this happens, likely most noticable when turning right or left as the axle wants to slide out in the direction of the turn. Don't forget to use red threadlocker on the abutment bolt threads.

Ed
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Old Dec 9, 2009 | 07:13 AM
  #4  
JamesC's Avatar
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From: Lawrence, KS
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: cant figure out WHY rear squeal

In my conversion, I used shims to center the carrier over the rotor (note the one in place and the three on the floor):

https://www.thirdgen.org/forums/atta...s-89-shims.jpg

Because GM has discontinued the shims, I purchased the ones seen above from AndyZ28 (two approximately .62 and two approx. 1.18 mm). I only employed one, a .62, on the pass side. Without it, the rotor would have hung up on the carrier.

JamesC

Last edited by JamesC; Dec 9, 2009 at 11:12 AM.
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Old Dec 9, 2009 | 10:26 AM
  #5  
transam85dudeman's Avatar
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From: CALI
Car: 85' Trans Am !best car ever!
Engine: 305tpi 215hp LB9 two bolt,
Transmission: th-700r4
Axle/Gears: stock (3.27)
Re: cant figure out WHY rear squeal

Brake hose maybe bad, JamesC mentioned a while back that they act like check valves when bad. mines doing the same thing, theres a center and a right rear brake hose, like a neoprene or rubber material. I have the exact same issue right now. while back i had brake failure, so i replaced the master and front brake hoses, got the solid pedal now when engine off compared to pedal touching floor. Regardless, the the rear Squeaks right after letting off the brakes until i get up to 10mph, therefore pinpointing the causing of the noise to brake hose or brake caliper. I got a rebuild kit from GM 8 months ago, but my noise is brake hoses not releasing pressure.. Shims sound like a great idea in general, but maybe after the brake hose swap. braking is supposed to be enjoyable without anxiety i say.
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Old Dec 9, 2009 | 10:42 AM
  #6  
JamesC's Avatar
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From: Lawrence, KS
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: cant figure out WHY rear squeal

Originally Posted by transam85dudeman
Shims sound like a great idea in general, but maybe after the brake hose swap.
GM used shims on 10-bolts with PBR's (when needed), 89-92, as far as I know. I assumed that the OP was discussing these brakes.

JamesC
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Old Dec 9, 2009 | 10:58 AM
  #7  
mooch1's Avatar
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From: montreal-canada
Car: 1985 camaro Z/28
Engine: 305 V/8 4bbl carb
Transmission: T5 WC
Axle/Gears: 3-23 posi with 4 wheel discs
Re: cant figure out WHY rear squeal

i had the same issue when i did my conversion...the rotor would hit the bracket just a touch and cause an annoying noise...i spoke to ed and he told me to put some washers/spacers between the axle flange and the brackets i got from him ...it solved the problem ..
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Old Dec 11, 2009 | 02:30 PM
  #8  
chevyboy07 91's Avatar
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From: down by the river
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Last edited by chevyboy07 91; May 1, 2014 at 03:12 AM. Reason: .
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Old Dec 11, 2009 | 06:21 PM
  #9  
transam85dudeman's Avatar
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From: CALI
Car: 85' Trans Am !best car ever!
Engine: 305tpi 215hp LB9 two bolt,
Transmission: th-700r4
Axle/Gears: stock (3.27)
Re: cant figure out WHY rear squeal

only passenger and center, no drivers side, its hardline. hmm, im ordering the hoses today.


*edit: i meant rear passenger and rear center.

Last edited by transam85dudeman; Dec 11, 2009 at 08:36 PM.
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Old Dec 11, 2009 | 07:41 PM
  #10  
chevyboy07 91's Avatar
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From: down by the river
Re: cant figure out WHY rear squeal

(transam dude)

we are talking about the rears....all hoses
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Old Dec 11, 2009 | 08:35 PM
  #11  
transam85dudeman's Avatar
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From: CALI
Car: 85' Trans Am !best car ever!
Engine: 305tpi 215hp LB9 two bolt,
Transmission: th-700r4
Axle/Gears: stock (3.27)
Re: cant figure out WHY rear squeal

sorry i meant rear passenger and rear center. i got the driver side factory hardline. different cars i guess

Last edited by transam85dudeman; Dec 11, 2009 at 08:43 PM.
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