It is a castle nut, thread is 3/4-20, not 3/4-18. IT IS 1-1/4" ACROSS THE FLATS.....Best source is off a Hudson parts car, or via one of the Hudson part vendors. It is a high strength steel somewhere along grade 5-8, as it is torqued 125-200 foot pounds. There ARE spindle nuts for the front wheels in that 3/4-20 thread, but are NOT suitable for the rear axle shafts as these are not intended to be torqued up, and they only have 1-1/16" across the flats.

Thanks for the correction on the pitch-dark my pitch gauge is as old as the car and " slightly" corroded...off to check again on the web!

As I said before, you will save a lot of time sourcing these castle nuts from one of our Hudson suppliers, there are not equivalents available new online.....

Try Larry Cramer by Saranac Lake, he may have those axle nuts.

Thank Ken, I just shot him an email. Much appreciated!

Rock Auto have those as an Oldsmobile spindle nut spare. They are also used on the Essex 4 differential.

[quote="David Young" post=27093]Rock Auto have those as an Oldsmobile spindle nut spare. They are also used on the Essex 4 differential.

I must reiterate on my previous caveat about using that spindle nut: "There ARE spindle nuts for the front wheels in that 3/4-20 thread, but are NOT suitable for the rear axle shafts as these are not intended to be torqued up, and they only have 1-1/16" across the flats.".

Thanks Folks! Proper nut has been procured via Larry Cramer. Next question: what's the largest (highest) tire I can run on my Jet? I was thinking about a 215/75-r15 to help reduce the rpms a bit... currently have 205/65

If not, give us a call, we should have it.
WRP 317-398-4163.

Andrew,

You might consider bias ply tires. They stand a bit taller than radials, and the steering is also lighter when using them. I have them on my '49 Hudson, and have driven twice from Boston to California and back with them. I also appreciate the slightly larger diameter, for the reason you mention.

Per

I have my Jet on 6ply rated 670/15 bias ply tyres, and it handles well. Probably not as good as radials, but you learn to drive accordingly, and the diameter brings the speedo right, and has just enough room to get the rear wheels off. Much quieter than radials, and steering is lighter.

I may consider the ol bias ply...but it's had radials since I bought it, and I've grown rather used to them. It's truly not something that I have to decide on immediately, I'm running snow tires until April. Planning ahead.