Weird issue on my 88 GT 5-speed. Driver side rear brake dust shield hitting rotor!!! (Page 1/2)
phils88GT DEC 16, 11:05 PM
Hey Everyone! I have an ongoing issue on my 88 GT 5-speed. When I first got it, I found that the driver side rear brake dust shield was rubbing on the brake rotor creating a very terrible noise. So, I figured at some point in the cars life, someone handled the dust shield the wrong way and bent it towards the disc. So, I saaw a place or two where this appeared to be happeniing and bent it back out so at no point was the dust shield contacting the rotor.

I thought I had it fixed, but while driving today, I found thet when taking a moderate right turn at say 20mph or so or above and pressure started apply to that left rear wheel, you could hear the dust shield making contact, although not as hard, but still very auible!

How the heck is this happening? How could this flex enough to make contact?

Thanks,

Phil
Notorio DEC 16, 11:57 PM
Are you sure it is still the dust shield hitting? I had an eBrake cable rubbing the tire in turns to one side, and not the other. Just a thought -- if you are looking at the geometry with the rear supported by the cradle, and the wheel hanging and then removed, this doesn't show you the up-travel that the 'live' suspension actually sees. In my eBrake example, which may or may not be your problem, I could only see the rub with the wheels normally loaded.
theogre DEC 17, 12:00 AM
Check all the rotors & shields.

On most vehicles Wheel bearings, loose type or sealed the a hub unit, do not want preloading & have some play to start...
Bent shield as you seen.
Aftermarket rotors made wrong may not have enough clearance.
Hubs maybe going bad.
All can hit during turning.

Hubs are not made to be raced & die faster.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

sdgdf DEC 17, 03:13 PM

quote
Originally posted by phils88GT:

Hey Everyone! I have an ongoing issue on my 88 GT 5-speed. When I first got it, I found that the driver side rear brake dust shield was rubbing on the brake rotor creating a very terrible noise. So, I figured at some point in the cars life, someone handled the dust shield the wrong way and bent it towards the disc. So, I saaw a place or two where this appeared to be happeniing and bent it back out so at no point was the dust shield contacting the rotor.

I thought I had it fixed, but while driving today, I found thet when taking a moderate right turn at say 20mph or so or above and pressure started apply to that left rear wheel, you could hear the dust shield making contact, although not as hard, but still very auible!

How the heck is this happening? How could this flex enough to make contact?

Thanks,

Phil



This may be bad advice but I run mine without them. IIRC they don't work with my rotor upgrade anyway. I don't drive my car in rain though, and its not like I offroad it or anything. My rotors are always clean when I check my brakes. In a daily driver I'd very much recommend keeping them.

[This message has been edited by sdgdf (edited 12-17-2023).]

fierogt28 DEC 17, 11:18 PM
The brake disc shields can be a pain on any car.
The issue is when the mechanic removes the wheel, it happens that the wheel drops on the shield and bends and touches the rotor. Then the mechanic doesn’t notice the shield clearance.
Or when the wheel is tighten on, the rotor is now touching the rotor.
I always check the clearance every time the wheel is removed.
15 years ago did my car jelly2m8 took them off my 88GT, and that was a great idea, as they can be a pain in the a$$.
I once had this issue on my other 88GT, and will remove them in the future to prevent this problem.
There bolted on with 3 very small bolts.

I do remember the 84-87 shields were thicker front and rear.


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fierogt28

88 GT, Loaded, 5-speed.
88 GT, 5-speed. Beechwood interior, All original.

[This message has been edited by fierogt28 (edited 12-17-2023).]

cvxjet DEC 17, 11:25 PM
I was driving my Fiero 'round town and passed a truck- thought I heard something ("truck has a problem") then drove by a flat wall- same sound- but no truck...(Oh-oh)....so started checking things out left rear wheel- couldn't find anything...Next time I drove it loud screech! Came home and searched some more- and found a rock wedged between the brake shield and the rotor. Might check on that....
fierogt28 DEC 17, 11:56 PM
cvxjet, that is a perfect example of how you can hear this noise.
Even driving close to a high curb.

Your second point can happen too.
Funny how a small rock can end up in
a very, very small gap.


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fierogt28

88 GT, Loaded, 5-speed.
88 GT, 5-speed. Beechwood interior, All original.

[This message has been edited by fierogt28 (edited 12-17-2023).]

cvxjet DEC 18, 02:28 AM
I have been driving my Fiero since new May 1985- even on gravel roads (Like into Butte lake CG Lassen NP) and NEVER had this issue once- until this time! (And i swear it wasn't one the rocks from my head)
phils88GT MAR 06, 10:13 PM
So this saga just continues... I started dailiy driving my 88 GT to work this week. However, before I started, on Sunday, I took the driver side rear wheel off and bent inward the brake dust shield, I made what should be PLENTY of room between it and the rotor. I put the wheel back on and I will be darned if that freaking thing is still grinding when making right turns and left turns, although not nearly as much on the left turns. I just don't get how this is even possible!

What the heck could be allowing this much flex in this area? I did look at the maintenance history that the previous owner had and he did have that wheel hub/bearing replaced last year. The passenger side is fine!

I guess I am going to have to strip it down and look everything over. Going in a straight line, all is good! I am just baffled!!
jelly2m8 MAR 07, 12:40 AM
If that is a consistent thing on the same corner, you may want to check that Wheel bearing, that is the only thing that controls the clearance between the brake rotor and the Kunkle ( which the dust shield is solidly mounted to) Being a year old means nothing? The cheapest available part? incorrect Axle nut torque? Raise the offending wheel, grab it at 12 o'clock and 6 o'clock and lever the living hell out of it, if you feel anything, it's likely toast., Me I might even remove that rear wheel bearing / hub and see if it has any free play.

[This message has been edited by jelly2m8 (edited 03-07-2024).]