Warped hub flange - your thoughts?
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 3,697
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From: WI
Warped hub flange - your thoughts?
Guys,
Before I order a new front hub, can you think of any reason it would be (or appear) warped?
Backstory:
Never really drove this car (1981) before tearing it apart to restore/repair, so I don't have any experience with the brake from a driving perspective. I knew before I bought it, it sustained some sort off trama to the front driver's side wheel. Seller said he 'thought' the wheel fell off from the PO going down the road, but I think, judging from the scars left after the repair, etc, the lower ball joint broke, or they hit something (like a curb??). Frame's not bent, new ball joint, rotor, etc on that side. In the process of doing the brakes I put a dial indicator on the rotor and it measured .02 run-out (you read that right!). They should really bee within .004 (I know the book says .005 but..). The hub looks like it could have been replaced, or maybe was cleaned up. Regardless, i'm measuring .007 on the hub flange just outside the stud perimeter. That's with the spindle nut tighened, or slightly loose (didn't make a difference). The rolling action of the hub is free, smooth and normal (no bearing binding).
Sooo... question I have is, can you think of any reason I'm not thinking of, the hub would measure that much run-out, besides warpage, or poor workmanship?
Thanks
.
Before I order a new front hub, can you think of any reason it would be (or appear) warped?
Backstory:
Never really drove this car (1981) before tearing it apart to restore/repair, so I don't have any experience with the brake from a driving perspective. I knew before I bought it, it sustained some sort off trama to the front driver's side wheel. Seller said he 'thought' the wheel fell off from the PO going down the road, but I think, judging from the scars left after the repair, etc, the lower ball joint broke, or they hit something (like a curb??). Frame's not bent, new ball joint, rotor, etc on that side. In the process of doing the brakes I put a dial indicator on the rotor and it measured .02 run-out (you read that right!). They should really bee within .004 (I know the book says .005 but..). The hub looks like it could have been replaced, or maybe was cleaned up. Regardless, i'm measuring .007 on the hub flange just outside the stud perimeter. That's with the spindle nut tighened, or slightly loose (didn't make a difference). The rolling action of the hub is free, smooth and normal (no bearing binding).
Sooo... question I have is, can you think of any reason I'm not thinking of, the hub would measure that much run-out, besides warpage, or poor workmanship?
Thanks
.
Last edited by Mark G; Jun 3, 2020 at 03:52 PM.
Race Director
Joined: May 2006
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Is the rotor still riveted to the hub?
If it is can you drill out the rivets and start mounting the rotor back onto the hub one stud further over and rechecking run out to see if the run out can be reduced?
If it is can you drill out the rivets and start mounting the rotor back onto the hub one stud further over and rechecking run out to see if the run out can be reduced?
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 3,697
Likes: 833
From: WI
No it's not still riveted.
This was the 'damaged side' and they installed an aftermarket rotor. I did rotate it through each stud and no change deflection-wise. The Pass side IS still riveted so I can't swap rotors (not easily that is).
This was the 'damaged side' and they installed an aftermarket rotor. I did rotate it through each stud and no change deflection-wise. The Pass side IS still riveted so I can't swap rotors (not easily that is).
Safety Car
Joined: Dec 2012
Posts: 3,820
Likes: 1,728
From: Summerville SC
Since there isn't a lot of miles on it ( or at least your miles) maybe they replaced the hub but the bearing races aren't seated properly. Just throwing that out there. Not likely but maybe possible. Something I would check before buying a new one.
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 3,697
Likes: 833
From: WI
I thought about that too. Wouldn't tapered roller bearings 'bind' if they weren't seated properly? But yeah, I should look at that. The more I look at it it looks scored on the 'centering' part of the hub, maybe the wheel did get off-center and boogered up the hub. Which could cause the flange to warp. Just a theory. Thanks for the ideas...
Le Mans Master
Joined: Jun 2019
Posts: 7,658
Likes: 2,470
From: Indiana
Hub? Rotor has runout? Chinesium aftermarket?
pull, bearing inspection new seal rotor...
unless im missing something
ah the base hub..wouldnt a straight edge show a bent hub?
pull, bearing inspection new seal rotor...
unless im missing something
ah the base hub..wouldnt a straight edge show a bent hub?
Last edited by interpon; Jun 3, 2020 at 08:18 PM.
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Safety Car
Joined: Dec 2012
Posts: 3,820
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From: Summerville SC
Agree that the bearings would straighten themselves out , but I am thinking that maybe the races are not installed straight. If one or both are not square, that might throw it all off, even though the bearings are square in the race.
Safety Car
Joined: Sep 2005
Posts: 4,226
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From: Orange County Ca
The story is, that the hub and rotor were riveted together at the factory and then the rotors were trued up.
The rotor to hub interface is not necessarily true. When the rotor was replaced, this was all changed.
What to do now?
You have to shim the rotor to get it to run true. There have been threads here previously that will tell you how to do this. The 2 major procedures are to home make washer like shims from aluminum soda or beer cans, or, the method I used, is to buy tapered steel shims. I got mine from Napa, #BA803-03 Hub Correction Plate. They are available from other sources also. The tapered shims come in different thicknesses for whatever you need. I think this is better because you get 100% metal to metal contact. Although, both ways seem to work.
The rotor to hub interface is not necessarily true. When the rotor was replaced, this was all changed.
What to do now?
You have to shim the rotor to get it to run true. There have been threads here previously that will tell you how to do this. The 2 major procedures are to home make washer like shims from aluminum soda or beer cans, or, the method I used, is to buy tapered steel shims. I got mine from Napa, #BA803-03 Hub Correction Plate. They are available from other sources also. The tapered shims come in different thicknesses for whatever you need. I think this is better because you get 100% metal to metal contact. Although, both ways seem to work.
Last edited by Sayfoo; Jun 3, 2020 at 10:40 PM.
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 3,697
Likes: 833
From: WI
The story is, that the hub and rotor were riveted together at the factory and then the rotors were trued up.
The rotor to hub interface is not necessarily true. When the rotor was replaced, this was all changed.
The rotor to hub interface is not necessarily true. When the rotor was replaced, this was all changed.
Is my vette stock?? HAHA
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Whydo you think it’s the hub and not a bad rotor. You see .007 runout at the hub, but still think it’s the hub?
why not Take the rotor to a brake shop and ask them, or throw a straight edge on the worst part of the run out, + and -
Last edited by Rescue Rogers; Jun 4, 2020 at 11:29 AM.
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From: Connecticut, USA
Safety Car
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From: Orange County Ca
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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Thread Starter
Safety Car
Joined: Jul 2005
Posts: 3,697
Likes: 833
From: WI
My lathe is a little on the small side. It's just a mini-lathe ...but it may work. I hadn't given it much thought until it was tossed out there. Ideally it should be rotated on a spindle to get it 'true'. Might take a while to rig something up.
Last edited by Mark G; Jun 4, 2020 at 11:57 PM.
Is my vette stock?? HAHA
Joined: Oct 2015
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Why don’t you get the rotor checked?