BGLeduc

I needed to install spacers on the rear of my car to clear the passenger side oil lines. Using 7mm spacers requires 52mm studs.

The studs supplied by H&R with the spacers were actually the stock 45mm.....a story for another day...but needing to get the car ready for a big event, I purchased 52mm studs from a well known fabricator of various bits for Porsches. I will not name names right now.

The race shop I use examined them and found that the splines were not of the same pattern as the stock studs, in addition to being very slightly bigger in diameter, and would not attempt to install them. The vendor refuses to take them back w/o a 20% restocking charge, plus I pay shipping. We are talking $40, chump change in the Porsche world, but I don't take kindly to being ripped off for any amount of money.

The shop I use is highly experienced, and I have used them for over 10 years. They have nothing to gain in terms of refusing to install the studs I received (I am getting the correct studs from the original supplier of the spacers).

For those of you with experience installing longer studs on our cars, is this issue with the splines common? It would seem to me that if the splines are not of the same pitch, then the studs would not be secure, nor could the stock studs ever be re-installed. But, I am not a wrench, so I will defer to the collective wisdom of the Rennlist.

Brian

Edit: The stud on the left is the 52mm, the one on the right is stock 45mm. The splines on the stock stud are much finer than the aftermarket 52mm.

Steve Weiner-Rennsport Systems

Hi Brian,

Without more detailed information about the studs in question, its not possible to offer anything specific, however I can tell you that we use German OEM studs which have not been any problem in 35+ years.

Without a doubt, the splines and dimensions MUST be perfect to assure proper & safe installation so QC is critical. More and more parts are not measuring up anymore so its very important to choose suppliers and manufacturers quite carefully.

You can PM me with details for further assistance.

Indycam

The holes that the studs are pressed into are not splined to start with . The hole is cut and then the first stud is pressed in . The splines on the stud cut into the wall of the hole as the stud goes in . The metal deforms as the splined stud is pressed home . The splines on the stud and in the hole have two functions , first is to keep the stud from falling backward and the other is to keep the stud from spinning in the hole . The splines do not keep the wheel from falling off the car .
If you remove and replace the stud the fit the 2nd time will not be the same same . If you remove and replace a stud enough times it will become a slip fit instead of a press fit . When the stud becomes a slip fit some will tack weld it .
Changing the "pitch" of the splines causes a new set of splines to be cut in the old hole .
This is not a bad thing in and of itself .
Running a reamer down the hole when changing stud / spline count might not be a bad idea .

When I look at the photos of the studs , I don't see a problem .

Gus

I agree with Indycam - The extra spacing and taller or wider splines on the new studs will actually help cut a new grove and a little deeper for a better bite - this is a good thing if you replace studs often. The new stud splines will bite and hold better over installing a set with the standard spline diameter. FWIW.

jcs_911

Pretty much the best advice I ever got on wheel studs - "We only ever use Porsche studs. You just don't want them to break."

Merle

I'm gonna have to play the devil's advocate here and say that just because a stud is factory Porsche doesn't make it superior. Porsche head studs come to mind. I'm sure there are wheel studs that are just as good as or even better than the stock ones.

Indycam

http://www.summitracing.com/search/b.../?autoview=SKU

http://www.roushyatesparts.com/Drag-...tuds-s/730.htm

http://www.jegs.com/p/JEGS-Performan...23958/10002/-1


If I put 5/8ths studs on my VW Van , would you laugh ?

Indycam

OK

bdc1

bumping this old thread with a question; what is the exact length of the stock wheel studs?

The original post mentions 45mm - is that the length of the entire stud, stud without the base, or just the threaded part?

I've also heard someone mention 52mm

just want to be sure before I order longer ones and I can't check on the car right now because I'm travelling...

robt964

They're measured in the same way you'd measure a bolt.

bdc1

ok, and to confirm, 45mm is correct for stock studs?

Rocket Rob

Yes, the stock studs are 45mm

911PERVY

Yes, 45mm stock, thats the length of the threaded part and the serrated part but not the "top hat", overall would be about 3mm longer