I'm considering converting my rear hubs to wheel bolts by welding a nut to the back of the hub. I cant envision a problem but is there anything I'm missing? I want to do this becasue I have 11 inch wide summer / track wheels that need rather thick spacer and 9 inch All Season wheels that dont need the spacer. The fixed wheel studs would then be too long for my All season wheels and tires. Having a set of wheels with long wheel bolts and another set of wheels with short wheel bolts seems to solve the problem. Anyone have any thoughts on this?

 

Wouldn't bolt-on spacers avoid that issue?

 

Bolt on spacers are a bit of a kludge and I dont know if they are ok for the track. Hard to check them before going out....Even so I considered it but I need a 15 to 19mm spacer and the smallest bolt on I could find was 25mm. 25 woould require body work...I already rolled the fender so for many reasons the bolt doesnt seem workable in my case.

 

the 1989 GT used a 17mm bolt on spacer

 

Why would you need to weld a nut on the back of your hubs? The hubs are already threaded for wheel bolts. The studs screw into the hubs. Just unscrew the studs and the threads are already there. Am I missing something here??

 

yes, 928 has pressed in studs.

 

Older Porsche's used studs pressed in the hubs with wheel nuts. The later model vehicles use a one piece nut with a cone shaped washer attached to it. I believe the one piece nut is more economical to produce, which is probably why they made a change. (This started with the 996's and Boxsters, when the bean counters took over.)

Studs are really nice....you can lift up a tire and wheel, slide it onto the studs and it will stay there. I've found holding up a tire and wheel on a later car, while you attempt to start the once piece bolt a bit fumbly.....and as the wheels get wider and heavier, it gets worse.

 

I just got a wheel hanger alignment tool. Solves the problem quite nicely. I'm just barely strong enough to lift the wheels on my Cayenne and since I got the tool, life has been much easier.. I do wish they had a bolt head on the end though - that way I could zip them out with a power tool.

 

I wouldn't be welding anything to a hub. That is probably heat treated metal, and a critical, highly-stressed part. Welding screws up heat treating.

When you say the studs would be too long without the spacers, do you mean from a cosmetic standpoint, or because you have closed-end lug nuts?

 

Likely have a set of extra long studs if you are in need. PM me if so and I'll dig them out.

 

Here's what worked and what I'm comfortable with at this point given I'll be on a track in 9 days and still have lots of prep to do.

Bolt on 20 MM spacers.

They're the thinnest hubcentric bolt on spacers I could find. They're also thick enough to hold the wheel studs and the conical seats and nuts appear to be very high quality. They took torque well. They push the wheels out as far as they can go for a track friendly disposition but I did have to roll the lip. I did a test drive pushing the car from side to side as aggressively as I could at 80 MPH and there was no rubbing. I thought 19mm was the max spacer I could do but 20mm worked.

Slightly off topic...I cant say enough about the Michenin Pilot Cup 2 tires. They generate nausia inducing grip that I still need to get used to. They're also quieter and ride better than the Continental DWS 06 All seasons I had on the 928 by a wide margin. I'm not sure what wheels these are but they are far bigger (19x11) and noticeably lighter than the (18x 9) inch Panamera wheels that came off. Kind'a interesting one can fit 19x11 wheels on a 40 year old OB design with just a lip roll.


Most interesting to me...
I had 15mm spacers on the rear first but they were not hubcentric. There was some offset related squirm an vaguery since the front offset is ET53. It seems to have disappeared with the 20MM spacers. I dont know how that's possible but the reduction in the little squirm I had and improved on center feel was clear to me. This evening's rather spirited test drive felt more like my previous Panamera wheel setup which has nearly the right offset.

 

I recall that some clubs used to frown on aftermarket bolt-on wheel adapters ("spacers"). I don't have a strong opinion on whether they are OK or not, but its might be worth checking whether the club you're running with cares about that.

 

I'll say it, are you friggin insane? Wheel bolts with "welded" on nuts? WTF????

 

Thanks Gary.... your comment is really on point and relevant now.

 

Great, i'm here to help!