Does anyone know the size of the rear diffs pinion nut? It's a 12 sided nut but I'm unsure of its size.

 

Do you mean the one that holds the pinion flange on? It's a self locker if it's the one I'm talking about and you can only use it a couple of times before replacing.
Are you replacing the pinion seal?

 

Nope M8, the 12 sided nut the holds the pinion in the diff itself.

Looks like its might be either 36mm or 38mm but I can't get it off untill I make a tool to suit but I need a 12 sided socket 1st to fabricate a tool.

The 'other' nut you are on about is just a 24mm locknut that holds the driveflange on, that ain't a problem

 

Ah right, the one you need to take the circlip off for. You can get a special wrench to take off the star type nut

 

No circlip there (nor should there be ) I think you are getting mixed up with the crownwheel

 

and i think its left hand thread!

 

No idea really chap - I only got as far as replacing the pinion oil seal so didn't get down that far. I'm just going from what the Ford manual and diagrams say as I got them out to do the oil seal. It shows a special star wrench to remove that nut and putting a chisel in the circlip groove

 

Yes it is

I have a 'mangled' nut looks like it 'might' be 38mm but I've been told that the 'might' be 36mm but not sure.