Fitting some new wheels, and needed a bit more length on the studs.

The front hubs are cortina, rear Sierra

Studs that are in are 40mm lomg M12 x 1.5

When I offered the wheels up, the only had about 3 full turns on them.

Hub is approx 10mm thick, the disc 8mm and wheel 8mm, so total of approx 26mm, but the nuts are not threaded all the way to the end, hence only 3 turns


I bought some 47mm long stud 13.1mm splines, as I thought the sierra hubs had holes to suit these.

But could I not fit them

Using my impact wrench I managed to get them within abot 10mm of going in but wrecked the nut I was using totally



hub stid 1

Managed to bash it back out and realised it was the wrong size



hub stud 2

hub stud 3

the shank on the original is only 12.6mm and the spines 12.8mm
the replacements are 12.8 and 13.1.


So the questions are.

firstly do I need longer bolts than the 47mm, as these will only give me another 3 turns or so?

Do I drill the hub holes larger or try to find some other bolts that have a smaller spline?

Can you get 12.8mm splines?

Why would by sierra hubs be 12.8mm.

I don't want to drill the hubs and find the studs spin

[Edited on 16/7/2017 by Trev Borg]

I recently replaced rear Sierra studs with 63mm 13.1 spines. I removed the drive flange and bashed out the old studs and hammered in the new ones. I don't think you have the wrong size maybe the way you are trying to fit them.

Edited: Hub to drive flange.

[Edited on 19/7/17 by Smoking Frog]

Bought a couple of different one today, and they vary a fair bit. The original ones had a much wider band of splines than the new one i bought.

The one I took out of the rears were the correct size for the fronts, so they went in ok.

I decided to file off a bit of the width of the splines and although very tight have gone in.