Datsun Roadster Forum-311s.org

Hi all,
I know this topic has been discussed in the past, but I still can't find a definitive answer on the forum. I tried the Moss Motors nut (part 311-065) on my 67.5 a while back and it was not a good fit. Someone said it worked fine on the earlier (65-67) cars.

So does anyone know the correct thread size and pitch for either the 65-67 or the 67.5 pivot heads. It sounds like they may be different. I want to purchase a die to clean the threads up.

Thanks for any information you can share.

Mike

Mike, I have a 1967. I took my original Pivot nut down to HD and it started to thread onto bolts 16mm x 2.0 then stops, same for 5/8-11. Yours should be metric. If I had to guess, I think the pitch is 1.5. Maybe you can track down inexpensive nuts to confirm what fits on your threaded Pivot stud. I'd try to find one each 16mm x 1.5, 1.25 and 1.75 to cover the possibilities. When you track it down you can then buy the Die / Tap you need to clean up your OEM Nut.

Not sure why these are loading upside down. I rotated the original files and same results.

I bought the MGB nuts a couple different times for my 66 and 67. I had some that fit perfect and a couple that were loose. I don't know if it was the pivot but I'm supposing the nut. I thought I had bought them all from Moss as per the wiki.

Dennis, that's a good idea. I'll do a little trial and error at the local Ace and see what I can figure out...

Curtis, it seems like the half years cars weren't always consistent with sae vs metric on some parts and just used what they happened to have on the assembly line. It makes it interesting.

Thanks for the replies.

Don't know but that would be usual for them. I bought the same exact nut for 66-67.

Hi all,
So the correct size and pitch for the stock nut that secures the wiper motor arm pivot to the cowl on a 67.5 is M16 x 1.0 (ultra fine). I couldn't find anything close at Ace and ordered a few on Amazon to check for fit, and they work perfectly. The Moss Motors nut is slightly different - I'm assuming some sort of British thread. So if you have a Moss Motors nut, you could run an M16 x 1.0 tap through it and make it work. I can't speak to the earlier 65-67's, only the 67.5's.

I hope that helps someone.
Mike

So I just looked on line and a lot of fastener houses have them in stock. The correct reference is M16 1.0 “jam nut” or “half nut” which will give you the correct thickness or hight. They had a several different hex sizes, so you will need to keep an eye on what hex size you are ordering.
Dave

This is great info about what seems to have been elusive info.

Thanks Mike and Dave for the research!

Peter

So, thanks to Mike & Dave, M16 x 1.0 apparently works for 67.5 and newer. What about 65-67? Did anyone ever confirm if they're SAE or Metric? If SAE, what? 5/8 x 18?

Thanks.

ppeters914 wrote: ↑Sun Aug 06, 2023 7:19 pm So, thanks to Mike & Dave, M16 x 1.0 apparently works for 67.5 and newer. What about 65-67? Did anyone ever confirm if they're SAE or Metric? If SAE, what? 5/8 x 18?

Thanks.

Even with my readers on and bright light I can't be sure (thread gauge) but I have an early 1967 and my original nuts are either 28TPI or .9mm thread. (28TPI = .907mm) so that is why I can't really tell which is which as they are near identical. It appears that these nuts are often referred to as jam nuts. I don't see 5/8 x 28TPI nuts / bolts available although tap and dies are available to make them. Nor 16 x .9mm. Whatever it is, it's close to the 16 x 1mm of the later cars.

The Datsun roadster has some now obsolete threads.

I used a magnifying visor and 27tpi fits perfectly.

Per the wiki I purchased 2 sets at different times of the MGB nuts. The first one fits perfect. The second one although has the right thread pitch but is too big of a diameter.

From 311s wiki.
MG Parts---Wiper Pivot Nuts--311-065 Chrome ----Around 3.00 ea. Rubber gskt / Seal 282-820 Around 2.75 ea. Moss Motors 800-235-6954 (I know for a fact these fit a 67.5 as I used them on mine.)

https://www.mcmaster.com/products/nuts/ ... ze~5-8-27/