NA to NB subframe swap
 

So it appears the pinion on the steering racks are different diameters...

Does anyone know if I need just the NB steering column U-Joint at the rack end, or the entire column?

Bill

Ooh. I did not know this.

I did not know this either. Call FM?

I'm going to run by the auto recycler tomorrow with the pieces to see what I can do. Weird I had never heard of it. The pinion from the 2000 looks to be 1-2mm larger.

any word on his?

When FM swapped in the NB subframe during my build, the steering rack had to be changed too.

Yes but the intermediate shaft (Portion with two U-joints on it) from an NA doesn’t fit the splines on the input to an NB rack.

What I don't know is if I get an NB intermediate shaft will it fit an NA steering column or are the splines on that different too?

Bob

I'm pretty sure I have a complete NB steering column in the shed. Anything I could measure that would help?

Given that my steering column is original, I would hazard that an NB intermediate will do the trick. To be safe, a quick call to Keith will get it sorted out, as he advised me the first time around.

NB intermediate to NA steering column here

Sweet thanks bros

Heh, I'm going through this right now. Just an hour ago I tried pushing the NA u joint onto the NB steering column only to realize, in horror, that it didn't fit...

Found this thread, and to verify called FM. Keith didn't actually know about this issue, but apparently Kyle did. Kyle got out the steering parts to confirm and agrees with the conclusions here. The u joint is bigger on the NB, and the intermediate shaft that bolts to the u joint is also bigger, so both of those need to swap, but the steering column in the car receives both gen intermediate shafts. So, I need to get the u joint and intermediate shaft.

Looking for some updated info on the NB subframe in a NA. Above some say I just need the intermediate shaft (double U joint?) some say the intermediate shaft is something other than the double U joint.

I have a complete subframe with rack and double U joint all ready to go in.

I just completed the NA to NB subframe swap. It was quick and easy. I got it complete with steering rack and U joint that connects the rack to steering column. No need for any intermediate shaft etc.

It took longer to do the research than it did to do the swap. Looking forward to some decent camber numbers out of the front.

I wouldn't expect much if any more camber out of the front... It's more of a caster thing as well as a little better camber under bump.

I was told due to camber gain at my 4" ride height static numbers will be better. If I hit 3 degrees I consider it a success.

Bump steer should improve as well.

Just got the car aligned with the NB front subframe. Getting 3 degrees of negative camber at 4" ride height was easy. There is about another .5 of adjustment left before maxing out. Prior to the change 2.8 L / 2.5 R was the max.

The caster is set at 5 degrees. I spaced and forgot to give a caster spec to the alignment shop. Gonna try it for a day or two and see how it feels. All the race guys say go for max caster. SOP for de-powered Miata rack is 3.5 degrees.

Thanks for the update Thomas.

I just did mine as well.
NB rack, NA column. The little shaft with the boot, is that what y'all are calling the "intermediate" shaft? If so, it is an NB piece and splined perfectly with my NA column.

https://www.miataturbo.net/attachmen...ine=1363221459

Whew! Thanks for the picture doward. I thought I was going to need more parts to complete my swap, but if that little boot piece is the intermediate shaft then I'm home free.

Also: If anyone is doing the rear subframe swap, and plans on keeping a NA catback and hangers, the hanger you need to relocate is on the rear driver's side of the subframe. It needs to be moved ~5.5" inboard from its current location.

https://www.miataturbo.net/attachmen...ine=1363295440

Found the picture over on the other site, but think it would do well hosted here for posterity.