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Rotors Moving/Clunking

Old 06-15-2011, 10:08 AM
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Exclamation Rotors Moving/Clunking

OK so I know that the rotors are moving. I can see it when I spin the front wheel in one direction and someone in the car hits the brakes. The rotor turns and clunks against the wheel studs. The size of the stud and the size of the holes in the rotors are different enough that there is some play in them. I am using Powerstop rotors and had a pair of rotors that did the same thing before these. It is not a good sound and only does it when I change the travel direction from forward to reverse and reverse to forward. The rotors only move once but I still donít like the fact that it happens at all. The car has 36,000 miles on it.

Has anyone had this same issue? How did you fix it?
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Old 06-15-2011, 10:41 AM
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are your lug nuts torqued to 100ft-lbs. The wheels are really the only thing that holds the rotor against the hub.
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Old 06-15-2011, 11:14 AM
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Iíve torqued them to 100ft/lbs, 125 ft/lbs and 140ft/lbs with the same results.
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Old 06-15-2011, 12:27 PM
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My car does this too. I was thinking it was the retainer clips on the calipers not holding the brake pads still. I have aftermarket pads on the car now. My stock pads don't make the noise, but I don't like the way they feel (clamping force) when I step on the pedal, so I run the aftermarket pads and just live with it. However, they didn't make noise when they were new. But I don't remember when and at what point of wear they started moving in the calipers. At least, thats what I think is going on...
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Old 06-16-2011, 09:41 AM
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Well I know for a fact that the rotor is moving. I took the wheel off, torqued the lugs to 100ft-lbs, spun the hub and had someone hit the brakes. You can see the rotor turning. There must be a 1/16" or so of play in the rotor holes for the wheel studs and the rotor just moves.

What should I do here, anyone?
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Old 06-16-2011, 12:01 PM
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All rotors come like that. ive never seen a rotor not come with slightly bigger holes like your explaining. Dont know what to do as i never had a rotor move before like that.
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Old 06-16-2011, 03:48 PM
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Originally Posted by Badazz 97 TA View Post
All rotors come like that. ive never seen a rotor not come with slightly bigger holes like your explaining. Dont know what to do as i never had a rotor move before like that.
Right!...I'm hoping that this won't damage the wheel studs or cause something to break. I know how brakes work and know that the calipers and pads are not to blame here and that in the end the car stops but WTF.

Does anyone think this will cause the studs any undue stress? I'll have a machine shop make me something that will fill the gap in the rotor holes if it will reduce any safety issues. Slowing that car down is pretty important seeing as I drive it like I stole it.
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Old 06-16-2011, 04:38 PM
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I'm thinking that maybe all our cars do it and we just don't notice it. I mean, you have OEM style rotors and your wheels are torqued to 100ft-lbs.
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Old 06-17-2011, 09:26 AM
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Originally Posted by vjo90rs8 View Post
I'm thinking that maybe all our cars do it and we just don't notice it. I mean, you have OEM style rotors and your wheels are torqued to 100ft-lbs.
Good point. I guess I'll just keep my eyes (and ears) on this one. Still annoying though.
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Old 06-17-2011, 12:03 PM
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Weld them in place. They won't move then.

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Old 06-17-2011, 04:26 PM
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unless your studs are worn, or the stud holes in your rotors are elongated from them previously not being torqued right, or the lugs are not torqued correct, i do not know how they would otherwise be moving back and forth........hmm
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Old 06-18-2011, 07:11 AM
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Originally Posted by Undertow74 View Post
unless your studs are worn, or the stud holes in your rotors are elongated from them previously not being torqued right, or the lugs are not torqued correct, i do not know how they would otherwise be moving back and forth........hmm
The holes in the rotors, for the studs, as several folks have already noticed, are a bit oversized. Mine are also. You torque the wheels studs to 100 ft/lbs, but look at it this way....the brakes have to generate a LOT more than 100 ft lbs of torque, to stop a 3500 pound car. Therefore, the rotors are going to "move around" a little.



And yes, I've wondered about that a few times myself......
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Old 06-18-2011, 12:44 PM
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Originally Posted by leadfoot4 View Post
The holes in the rotors, for the studs, as several folks have already noticed, are a bit oversized. Mine are also. You torque the wheels studs to 100 ft/lbs, but look at it this way....the brakes have to generate a LOT more than 100 ft lbs of torque, to stop a 3500 pound car. Therefore, the rotors are going to "move around" a little.



And yes, I've wondered about that a few times myself......
I still think the pads have something to do with this. I changed from stock to aftermarket pads and my stock pads didn't make any noise. At one point I changed the rattle/retainer clips and the noise (aftermarket pads) stopped for awhile, but returned shortly after. Pads are just 'along for the ride' inside the caliper untill you press the brake pedal, clamping down on the rotor, making them move in the caliper even if it's just a little bit of movement. The rotor is clamped between the wheel and hub. If you torque each lugnut to 100 ft/Ibs, that's 500 ft/Ibs on one wheel, no? That's quite a bit of force to overcome. I'm pretty sure I'm not pressing down on the brake pedal that hard (to make the rotor move) to stop from backing out of my driveway or coming to a stop from 15 mph at the end of my street. I brought this subject up on Frrax a few years ago and the few who answered didn't think it was the rotor moving. Just my experience...
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Old 06-19-2011, 12:34 PM
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The rotor hat is crushed between the wheel and the wheel hub. It is the lug nuts and wheel studs that clamp everything together.

The wheel, brake rotor hat and hub become one solid assembly when correctly put together.

If you're tightening the lug nuts properly (as it appears you are) you need to look elsewhere as to why the rotor hat isn't being clamped properly.

What lug nuts are you using?
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Old 06-20-2011, 03:41 PM
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Originally Posted by Paul Bell View Post
What lug nuts are you using?
With the exception of brand everything is stock. Original stock lug nuts, original stock wheel studs, original stock wheels. The clips are stock and lock the pads in place. I really don't think they are a problem at all since I can't see or hear them moving when I "test" it all out.

I think leadfoot4 and others are right. I'm not doing anything wrong. I am just hearing it louder than others do. Which is surprising because the car has no mufflers and is undoubtedly the loudest car in town in the exhaust department.

I guess I am just being too **** but this is my only "toy" car afterall.
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Old 06-20-2014, 04:46 PM
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Hi I was wondering if anyone ever figured out why this was happening. I am having the same problem with the rotor moving when going from reverse to drive and visa versa. And for those of you saying that it can't be the rotor it is. I marked the rotor and my rim put it in drive and moved a lil bit and hit the brake, heard the clunk and then checked my marks and they were not lined up. I've called the technical support and they basically said that it's impossible and that there was something in the way. I've checked 3 times myself and even had a mechanic look at it and it's still happening, even when I over torque the lug nuts. I can't figure it out so if anyone has an answer please let me know. The only thing I can think of is to return the rotors and get a different set. Thanks.
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Old 06-20-2014, 09:16 PM
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Welcome to LS1tech!

It looks like you've actually searched and found info about your exact problem-bravo!

Can you take a picture of the mark on the rotor before & after it moves?

You'll need to put the pictures on a website like photobucket then add the links to them using the yellow photo box above here.
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