Have you ever seen a new brake rotor that is out-of-round?

[matthewr87]

Well now I can say that I have. My RH non-drilled rotor is a few mm out of round. I installed these rotors prior to my last track day and immediately noticed that the RH side front wheel was not spinning as freely as the LH side and seemed to be catching at a specific point. I had no time to swap them back for my old rotors so I finished the track day without incident (other than a slow speed squeak from the RH side when braking gently). I looked more closely today and could see that the RH rotor is out of round and at a specific point catches the brake pad. See pictures below for reference. I installed my old drilled rotors and this no longer happens. Has anyone had any experience with getting Motorcraft parts replaced under their 2 year warranty? I bought it from an online parts place that does not take returns but I can see on the shipping label they bought them from a Ford dealership.

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[matthewr87]

Anyone have any experience with the Motorcraft 2 year warranty for parts? Can I just take the rotor to my local ford dealership?

 

[_zOmbIE_]

Maybe it's just me, but I'd be using something a bit more scientific to determine if it's out of round than how your brake pad interfaces with it?

 

[19VelocityBlueGt]

Warped rotor. I doubt they would cover a warped rotor with warranty if you track the car. Doesn’t hurt to try tho. Usually that’s caused from getting them to hot..

 

[460Fred]

Show them this and your other post.
Didn’t you talk about this “before” you hit the track?

 

[matthewr87]

Show them this and your other post.
Didn’t you talk about this “before” you hit the track?

I posted another thread after coming back from the track but I detailed my experiences pre-track. The rotor was already warped when new. I noticed something was wrong right after installation when the RF wheel seemed to bind at a specific point when spun on the lift. I took it for a test drive and the car seemed to brake fine other than a thrumming and rhythmic squeaking from the RF wheel with light braking. There was no pull to the right while coasting or braking. I visually confirmed the abnormal runout today when changing the oil and doing another brake fluid flush. I switched back to my old drilled rotors which are still servicable.

As far as measuring the run-out more quantitatively I sadly have no way of doing so. All I can say is that the LH rotor does not exhibit this behaviour (binding against the pad at a specific point in the rotation) and when I re-installed my drilled RH rotor it was also fine.

As far as getting this rotor replaced I think I am SOL. When I spoke to the dealership that sold it to me I was told that since I was outside a 30 day window they couldn't do much. When pressed about the two year Motorcraft warranty the guy was pretty equivocal.

When I called a local dealership they told me the rotor would have to be on the car and I would have to pay a diagnosis fee and labor.

When I called another local dealership they said the part was not for my car (I have a 2018 not a 2019+).

So long story short looks like I am out $330. Not the end of the world but rather annoying on principle.

 

[shogun32]

So long story short looks like I am out $330. Not the end of the world but rather annoying on principle.

how on earth are you out that kind of money for the OEM rotor?
nevermind, GT350...

Take it to a 'brake lathe' shop and have them put a dial indicator on it instead of a cutter and they will be able to precisely quantify how much it's off.

 

[matthewr87]

how on earth are you out that kind of money for the OEM rotor?
nevermind, GT350...

Take it to a 'brake lathe' shop and have them put a dial indicator on it instead of a cutter and they will be able to precisely quantify how much it's off.

Sadly this all looks like it is going to be a significant time investment to try and remedy so I think I will just buy a new rotor and move on (hopefully a good rotor the second time around).

 

[Thor 142]

Seriously? We just accept bad OEM rotors on our cars?

how on earth are you out that kind of money for the OEM rotor?
nevermind, GT350...

Take it to a 'brake lathe' shop and have them put a dial indicator on it instead of a cutter and they will be able to precisely quantify how much it's off.

Seriously?! We just accept bad rotors on our cars?

 

[matthewr87]

Seriously? We just accept bad OEM rotors on our cars?

Seriously?! We just accept bad rotors on our cars?

I would rather have received a good rotor than a bad rotor, obviously. But it doesn't seem like there is any easy solution to this issue other than to just buy a new one and hope for the best. This "Motorcraft 2 year parts warranty" business seems like just smoke and mirrors.

 

[Thor 142]

I would rather have received a good rotor than a bad rotor, obviously. But it doesn't seem like there is any easy solution to this issue other than to just buy a new one and hope for the best. This "Motorcraft 2 year parts warranty" business seems like just smoke and mirrors.

I was responding to Shogun who said "nevermind GT 350" Like we should just accept shitty rotors. Is this for real?

 

[shogun32]

I was responding to Shogun who said "nevermind GT 350" Like we should just accept shitty rotors. Is this for real?

did you even read the crossed-out text? I was wondering how you manage to pay $330 for a single rotor. Then I realized OP was talking about a GT350 rotor...

The point of taking it to a machinist/brake-lathe shop with a dial indicator is to get documentation that SHOWS it's off. It's a lot easier to fight a warranty claim if you have measurements.

 

[JAJ]

If the rotor is off the car, I'd take a really close look at how it became bent.

First, in response to the folks who are trying to be helpful but don't have GT350's, GT350 rotors, all four of them, are two-piece compound rotors with an iron friction ring and an aluminum hat. The car rolled out of the factory with a BBK already installed. That's whey they cost $330 and it's also why you can't get cheap replacements from Autozone, although SHW, the OEM supplier to Ford, does sell them direct through Tire Rack. If you think about it, getting a pair of fully assembled two-piece directional rotors for $660 is pretty reasonable if you compare the cost to AP Racing or GiroDisc.

As to the problem with this rotor, the rotors have a ring of pins that hold the friction ring onto the aluminum hat. From the description, it sounds like the rotor might have been dropped or damaged, bending the pins or dislocating them somehow. If it were my problem, I'd take a close look at the way the friction ring sits on the hat. Set the rotor on a flat surface with the face of the hat down and measure the distance up to the edge of the ring at a few points around the outside. Once you know which way it's bent, see if you can see why. If the pins are out of line but otherwise undamaged, there might be a way to get it back to a straight position on the hat. It's unlikely but it's worth a look.

BTW, two-piece rotors shouldn't be machined at a machine shop - surface ground maybe, but putting one on a lathe is a serious risk to both the rotor and to the lathe itself.

 

[shogun32]

BTW, two-piece rotors shouldn't be machined at a machine shop - surface ground maybe, but putting it on a lathe is a serious risk to both the rotor and to the lathe itself.

the lathe was just a convenient way to use an indicator. it was NOT being advised to actually machine it. You can't machine it on the hat, it has to be fully dismounted first, and like you said, a surface grinder would be the proper tool of choice.

 

[JAJ]

the lathe was just a convenient way to use an indicator. it was NOT being advised to actually machine it. You can't machine it on the hat, it has to be fully dismounted first, and like you said, a surface grinder would be the proper tool of choice.

Exactly, and these dudes can't be dismounted. If you haven't seen one, it's a clever design for OEM use. The iron friction ring is made with a row of radial holes on the inside of the ring. A set of pins are inserted into the holes in the ring and the aluminum hat is cast around the pins. As the ring heats and cools, the ring expands and contracts by sliding out and in on the pins. The rotor can't warp and there's ample space for air to get into the cooling vanes. Very slick.

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