My fabrication guy is making me a lisc. plate bracket and needs to know if the rear axle is a 1" with a 3/4" thread size or what? Anyone have a clue? And if I'm not mistaken, the axle loads from the right side through to the left correct? I'm not in front of the bike right now. Thnaks!

 

25mm axle

 

Right to left is correct.
The nut is described as "FLANGE NUT, 3/4-16 (grade 5)"

 

That's the way it comes from the factory. But, if you're running exhaust pipes that extend back to the rear axle and block the axle from sliding out, it doesn't hurt anything to flip the axle around and slide it in from the left side.

 

wonder why they do not come like that from factory, having to remove the pipes to clear the axle is brain-dead.

 

I heard it's because of a safety thing in regards to the axle sticking in the bearing and unthreading the nut...but I can't remember where I heard that.

 

that makes sense, but if that is a mandatory safety thing a reverse thread on the axle nut would solve that.

 

That's partially true, but has more to do with the wheel spin direction. That's why Chrysler products for decades have used left hand thread lug nuts on the left side of it's vehicles.

Your Harley however, uses a cotter pin through the castle nut and axle to prevent the possibility of nut coming loose.

 

Yeah, I never investigated it...or cared. I only have one Sportster with pipes that extend back to the axle and I don't have any problem at all pulling it so it's not an issue for me.

 

...and to add to that...I am a suspension tech. When I'm doing a full restoration I will use a small cordless impact to remove all of the castle nuts with cotter pins. I don't even bother removing the pins if I'm replacing that specific piece. I just zip them right off. Even with a low battery. And from my personal experience, I can tell you that the pin on our axle is no match for the rotational force of a seized axle while simply cruising down the road. That pin is a last chance safety to retain the nut in a NORMAL situation when it is simply loose.

Just sayin...