Rear Wheel Studs

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Mar 24, 2019 | 09:07 PM

C4Newb

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Rear Wheel Studs

I am looking for a part number or source for studs I can install in the rear wheel flange of a '96 C4. My car came with C5 Z06 18X10.5, 58 offset wheels on it when I bought it, and I noticed that they are just kissing the inner fender liners at full compression, leaving wear marks. So the thought was to change to studs and add a 1/4 or 3/8 spacer.
I did try searching the forum but didn't find anything right off....
Thanks!

Sorry I meant to say longer studs....

Last edited by C4Newb; Mar 24, 2019 at 09:07 PM. Reason: Missed a detail

Mar 25, 2019 | 12:04 AM

James93LT1

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From: Hawaii

GM Part #22551491

Mar 25, 2019 | 09:08 AM

MatthewMiller

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From: St. Charles MO

Another option is ARP in three different lengths: 100-7713, 100-7725, and 100-7726.

Mar 25, 2019 | 09:32 AM

WVZR-1

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If your information is correct I doubt you need but a 'few mm' spacer to solve your situation. I doubt you need studs. If it just kisses the liner I'd work with maybe 4mm (likely less) and I'd think there's likely sufficient thread to work with. I believe you do much more before spending the $$$ for studs.There's likely off the shelf studs that might do well for you also if there's a need.

Last edited by WVZR-1; Mar 25, 2019 at 09:35 AM.

Mar 25, 2019 | 09:42 AM

MatthewMiller

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From: St. Charles MO

Quote:

Originally Posted by WVZR-1

To WVZR-1's point, 8" backspacing is about the max you can do without rubbing on a later C4.* You have about 2mm more than that. I agree that with 4mm spacers you'd clear just fine, and that's less than 1/4". 1/4" is about 6mm, and may be easier to find. Anyway, check your threads with those spacer thicknesses before assuming you need new studs.

*This assumes a typical tire width of up 295 for a 10.5" wheel. What size tires are on there now?

Mar 25, 2019 | 11:55 AM

WVZR-1

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OP - I'd think a conventional M12 flat washer is generally spec'd @ 2.25mm. I mentioned likely less suspecting 3mm required. I'd probably pick up some M12 washers and 'try' before buying a thing. Much in your case I'd think depends on what the 'witness marks' tell you. If the wheel-house liners are correctly secured, suspension in reasonable condition I'd think you need 3mm or less. The purchase of 1/4 or thicker I think likely - silly. I don't recall 'hub-height' but with 4mm or less you'd I believe maintain hub/wheel concentricity.

***Keep in mind that the thickness of the 'rotor hat' also effects what you need to consider. That dimension can change considerably in good, better or best and branding of the rotor.

Last edited by WVZR-1; Mar 25, 2019 at 12:14 PM.

Mar 26, 2019 | 07:30 AM

C4Newb

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Thank you very much for the replies. The tires are 295-35-18. The suspension is all new now, but was quite worn out when the witness marks were made (last summer). When I got the car it was noticeably tail high. I don't think the rubbing occurred until I installed lowering bolts in the back to level it out. Thanks also for pointing out the need to retain the hub centric location of the wheel, I had forgotten about that. Will give it a go with some temporary washers and see.....

Mar 26, 2019 | 09:07 AM

MatthewMiller

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From: St. Charles MO

Quote:

Originally Posted by C4Newb

That tire is within the range of stock tire heights that came on C4s throughout the years. Shouldn't be a problem in either height or width. So you're on the right track by finessing the offset.