BLUF: Yes, you can cheaply retrofit a 997 or 991 wheel onto a 996, at least on a manual car for about $53 USD. Airbag conversion TBD. Parts listed below.

I recently bought a modified 1999 C2 with a manual transmission for my wife to replace her s2000. We got a great deal and I think partially due to the fact that a lot of the interior had a lot of cheap "upgrades" that would push a lot of buyers away including crap sparco seats, harnesses, and cheap NRG steering wheel/quick release. Our first order of business has been replacing all of the mentioned parts with replacements more fitting to the experience we were after. For the wheel I considered moving to a Porsche classic wheel or standard momo equivalent but I am a bigger fan of the OEM+ type of experience. So I looked into installing a 997 or 991 wheel. I was able to find a banger deal on this reconditioned 997 standard wheel and airbag for 180 bucks shipped from a member here on the forum. I would have prefere a 991 wheel, but wheel and airbag together are about 5x the cost.



With that said, I thought, what's the worst that could happen if I try? Maybe I lose the cost of any conversion parts I order.

For those that don't know, 996 and older have ~17mm steering column spline and 997+ have ~26mm spline. I was curious if there were any options to adapt them together. From my research a lot of other people in the past have asked if it was possible but most responses were "no" or "only with the spacershop adapter that adds about 50mm of depth and costs 400 bucks on top of the price of the wheel. i couldnt find any solid answer, just a lot of "maybes". Fortunately, in various posts on the subject, I saw references to an adapter used on old VW and Audi cars that some said *might* work but I never saw any part numbers, links or even definitive evidence that it would actually work in practice. So after some digging I found this adapter that looked like it *should* work.

ECS Tuning Link
VW Part#: 377419514

A few days ago, it came in and it was a perfect match for the splines On both the wheel and steering column.

FITMENT: The splines on the adapter are a perfect match, but the adapter itself sits probably 5mm or so too deep on the column so the threads for the nut don't go far enough to clamp. Luckily it was an easy fix and I was able to find a thick stainless washer from my local hardware store with the outer diameter to sit flush to the mounting point on the 997 wheel without any interference and an inner diameter that matches the column. It only cost about $3.

After tightening everything down, the wheel looks and feels fantastic.


I still have more to go on this project regarding the wiring side, but for now, I'm happy with the result. I want to get the horn button and airbag working eventually, but considering that my old wheel was a quick release, I didnt have an airbag to begin with. For now, I removed the clock spring so I can examine the wiring to choose a route forward. The only thing visually that looks out of place is a small gap where the clock spring would have gone. Even with the spring it would probably have a small gap, but I'm thinking of making a fairing of some sort to fill the gap.

​​​​​​​More to come.

 

That looks good! Do you have pics of the steps in the process you might share?

 

Wow. Crazy how this makes the interior look better. I like the 4-spoke wheel, but I'd have this any day. Is the airbag still functional?

 

As of right now, the airbag isn't functional, but I am going to eventually figure that out. Shouldn't be a big project, just haven't gotten to it yet.

 

I just I have some photos of the adapter on the column and of the spacer/washer I used.




It's very simple from the mechanical side. Once the old wheel is off, adapter goes on column, then wheel on adapter, then washer/spacer, then original nut and washer.