Lock nut on end of pinion shaft

[flyboytroy99]

What size nut is on the end of the pinion shaft? I believe it's a 10mm, but what thread? Fine,or Super fine or what?
Thanks, Troy

[GTJIM]

I think you will find that the pinion nut is larger than M10.

More like M16 or even M18 and it is a Metric Fine thread - 1.5mm pitch.
There is a 'mushroom' stuck on the end of the pinion that is very important as it allows the driveshaft to bear against it.