1.8 bolt on drive shafts
 

What size is the stud on a 1.8 bolt on drive shaft please/

Paul

It's a special shanked bolt that cannot be replaced with hardware store fasteners. Order from a dealer or a breaker.

I've sorted it now. I found some press in studs (wheel studs) and used them.

Have fun removing the driveshaft with studs...

Methinks he may have meant these studs, which hold the driveshafts to the diff on the earlier cars:

https://www.miataturbo.net/attachmen...1&d=1426349543

I see no studs in that picture.

It took me a lot longer than it should have to realize that there are glowing green phallus in that picture.

I have used hardware store fasteners on the drive shaft to diff flange for many years now without issue. ever since I went from 1.6 to 1.8 diff and the bolts were bigger and I didn't have OEM ones.

Used 10mm metric flanged bolts and ground a flat on bolt head flange so it fits against the step in the diff input flange.

I used classic mini 3/8 wheel studs which press in lovely. If they can stand the torque from my previous racer which had more torque than this will then they should be OK. If not i'll over size the hole and press in the M12 wheel studs from the mx5 doner.

Paul