# Warped rotors?



## muohio (Sep 22, 2004)

I assume my rotors are warped as I get a lot of shudder in my steering wheel and car when braking between 45 and 60 mph. I don't feel it when cruising or accelerating so I doubt it's the tires being out of balance. With 11k miles, will the dealer warranty them? Other manufacturers seem to only warranty them for the first 10k miles. What is a good option for replacement if they don't?


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## Wing_Nut (Mar 6, 2005)

Rotors are a wear item but they shouldn't warp at 11,000 miles. GM should stand behind their product and probably will.

FYI, I replaced the rotors on a Volvo 850 Turbo at 110,000 miles after three sets of linings. They were no longer thick enough to meet spec. They never warped and never failed mechanically. That's a resonable expectation these days.

The rotors on my 05 GTO are thicker and larger in diameter than the Volvo as well as being ventilated at all four corners. The Volvo had solid discs in back. I certainly don't expect to have any problems.

Good Luck.


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## Jag Flash (Sep 26, 2004)

I get the same wheel shudder when I brake also, is that something characteristic of the gto?


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## Xman (Oct 31, 2004)

No, its a charactoristic of wrapped rotors. If the dealer won't cover it under warrantee then you have three options.

1) Remove your rotors, have your rotors turned at a local autoshop, reinstall with new pads. Consider using C5 front pads - they have almost double the contact surface and they just drop in. Note, some will argue the once a rotor wraps, turning it only pospones the inevitable (replacement) and they will wrap again - plus your typical shop can not turn them to the tolerance of a new rotor.

2) Get new aftermarket rotors, like Powerslots, that can improve performance. Again, use C5 brake pads. If you have an 04, consider replacing the rear rotors with 05 rotors and pads so you get the ventilated rear disks.

3) If you have an 04, go all the way and replace with an upgraded brake kit like a Baer 13-inch (stock 04s are 11.7-inch if I remember correctly).

BTW - the first thing any GTO owner should do is drop in C5 pads and bleed the brakes. The GTOs seem prone to coming from the factory with air in the brake lines. It took me two flush and bleeds before I got all the bubbles out. What a difference. My GTO originally didn't even have enough braking power to get the anti-skid to engage on dry pavement. Now the pedal is firm and the tires and road surface are what is limiting my braking.


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## Subdriver (Dec 28, 2004)

Warped rotors is likely not the cause of your problem. Uneven pad material buildup is more likely. Should be easily fixable by having the rotors turned if there is enough material left on them. I'll bet the dealer calls this a wear item and doesn't warranty the work. 

Here is a good article on the subject from Stoptech, a high performance brake company:
http://www.stoptech.com/whitepapers/warped_rotors_myth.htm


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## Groucho (Sep 11, 2004)

I warped my rortos at ~18k miles or so...and just took that as an opportunity to upgrade to PowerSlots. _Much _ better now.

The stock brakes on the '04 suck out loud.


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## bsmcall (Sep 11, 2004)

On my Goat, it's not the rotors. It is excessive inside tread wear due to the front alignment having too much negative camber. Turn the steering wheel all the way left, and examine the inside tread blocks on each tire. If they are uneven or visibly worn funny, rotate your tires from front to back, problem solved. 

EXCEPT MY DEALER REFUSES TO CORRECT THE ALIGNMENT ISSUE THAT FORCES THE FRONT TIRES TO WEAR IN THAT FASHION.


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## Xman (Oct 31, 2004)

If I understood the article - "warped" rotor is not correct but the end result, an uneven rotor surface, is the problem. All the steps are still valid above with the addition of one more. 

0.5) If the vibration is slight and just started, try some new semi-metallic pads, break them in, and see if their abrasive nature will removed undesired deposits from the rotor surface. If successful, there is no need to execute any of the following steps unless there is a personal desire.


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## muohio (Sep 22, 2004)

Subdriver said:


> Warped rotors is likely not the cause of your problem. Uneven pad material buildup is more likely. Should be easily fixable by having the rotors turned if there is enough material left on them. I'll bet the dealer calls this a wear item and doesn't warranty the work.
> 
> Here is a good article on the subject from Stoptech, a high performance brake company:
> http://www.stoptech.com/whitepapers/warped_rotors_myth.htm



Thanks for the article. I would bet that I have uneven pad build up as after getting my C5 pads on, I had to make a really hard stop on the freeway and I remember seeing the imprint of a pad on my rotor. I was really never aware of the bedding process for brake pads and honestly, that should be explained to everyone, if not performed when getting breaks serviced. The vibration is very bad on my car and I'm not sure if machining them will fix the problem.

As far as the Baer kit, I'm sure that's good for racing or eye candy, but for everyday use, the stock breaks with C5 rotors work well enough. I've seen write-ups by Stoptech where they show that aftermarket brakes really don't affect stopping distance, but improve fade and feel. I don't experience fade in daily driving and don't plan on auto crossing the car.


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## 79TA&04GTO (Jul 29, 2004)

I warped mine at around 7K?! I got into one of those "oh s**t" situations where coming around a bend at 130, the light about 1/8 of a mile up the road turned red. There have a been a few times I've had to hit the brakes pretty hard, but that was the worst situation. Just waiting for the day to convert my 04 over to the baer brakes front and back.


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## JuniorCruzer (Mar 28, 2005)

I am having the same issues with my car. I only have a little over 4,000 miles on my car. I am goig to take my car into the dealer this week and see what they say.

Jon


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## GTO-Quikls2 (Mar 21, 2005)

No problem with the GTO yet, but I have had a "warping rotor" problem with every GM car we have ever purchased. My wife's 99 Grand Am went through three sets of rotors (the dealer said it was the way she drove) two covered under warranty (one at 4,000 miles and another at 12,000 miles). My first Trans Am had the rotors replaced, our Grand Prix had the rotors replaced, and my WS6 had two sets replaced. To this date GM still says they do not have a warping problem, but rather it's a driver issue. GM brakes warping have been an issue with us since 1996 on our GM cars.


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## Snap (Apr 2, 2005)

I wouldn't discount warped rotors.
Just cured wife's Passat with new rotors.

There is no point in turning them down. Once the material is heated enough to warp, it's metallurgy is changed. They will continue to deform.

You can probable find pretty cheap replacements on the internet. The Passatt's were $30 shipped each on line; $85 at dealer; both the same name brand.


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## GTO-Quikls2 (Mar 21, 2005)

That was the only saving grace on our GM cars... the rotors were cheap. I would never just turn one down.


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## Subdriver (Dec 28, 2004)

bsmcall said:


> On my Goat, it's not the rotors. It is excessive inside tread wear due to the front alignment having too much negative camber. Turn the steering wheel all the way left, and examine the inside tread blocks on each tire. If they are uneven or visibly worn funny, rotate your tires from front to back, problem solved.
> 
> EXCEPT MY DEALER REFUSES TO CORRECT THE ALIGNMENT ISSUE THAT FORCES THE FRONT TIRES TO WEAR IN THAT FASHION.


This is a common comment on the Vette forums as well. Negative camber improves handling at the cost of inside tire wear if you don't drive hard enough to get similar outside edge wear. That said, excessive wear on the inside edge of the front tire doesn't indicate an alignment "problem" as much as indicate what the designer's thought process was: handling over wear.

In addition, the normal factory tolerance is pretty wide. I don't know the GTO numbers, but for example, the stock Z06 front camber is -0.7 +/- 0.5 degrees which means anywhere from -0.2 to -1.2 is "in" spec. That is a huge variance.

If you want less wear specify the dealer align your car to the low end of the GTO camber tolerace vice the middle or high end. They can hit camber within a tenth or so. 

Another big impact for that front inner edge wear is the front toe setting. Toe in or out increases the wear due to "dragging" the tire along the ground. I suspect that zero front toe in is within spec. Setting front toe to zero again will sacrifice handling (less turn in and more understeer) but increase tire life. 

On rotors...
I suspect most of your cars are still under warranty. But for those that aren't, or for those that would rather do your own work, check out NAPA for OEM rotor prices. For the Vette, best stock price is around $65-$75, NAPA is $25. The stock vette rotors are made in Brazil. I have been buying NAPA rotors for over a year now (I go through a lot on the track) and they have all been made in Canada or USA. :cheers


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## muohio (Sep 22, 2004)

I had them turned and the problems are gone. Guess it was nothing more than uneven brake build-up.


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## Subdriver (Dec 28, 2004)

muohio said:


> I had them turned and the problems are gone. Guess it was nothing more than uneven brake build-up.


Congrats. Glad to hear it was an easy fix. :cheers


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