36-40 clutch

[Steve Little]

Hi all.
I am in restoring a 37 EL. At the moment I am cleaning and checking a complete clutch that I bought on eek!Bay late last year.
After washing all the plates, drum, hub, springs etc, I thought I might do a dry run and fit it all to the trans which is sitting on the bench.
This is my first play with a 36-40 clutch and I remember reading or hearing about problems setting this clutch up or maybe it was operational difficulties with this early clutch. So I thought a setup on the bench would be easier than sitting on a 20 litre drum, and trying to do it with the trans in the bike.
The first part that I tried to fit was the hub to the gearbox main shaft, and then screw the left hand thread, tube nut to the mainshaft to check the run out.
But the tube nut wouldnt screw on to the mainshaft.
After a quick inspection I could see that some previous owner had marred the first three internal threads in the tube nut.
I tried cleaning it up with a thread file but it is hardened and just laughed at my puney efforts.
When I rang a shop for a new nut, the guy said he has 2 styles of this tube nut and they have some in NOS.
The nut that I have is 2.800" long and he said they have this and another style that is 2.600 long.
Obviously one is a later improvement, but I have no idea which.
If anyone has played with these clutches and can advise if the short or long nut is and advantage, let me know.
Regards Steve

[villy]

Hi Steve.
According to SHOP DOPE volume II the old style clutch had the short version from the beginning,then Bikes that left the factory after february 1 1938 had the new long version, (2 51/64").......do no why???
Hope that helps.
Villy

[duffeycycles]

steve look at palmers how to restore-page 335

[Steve Little]

Thanks for the info Villy and Duffey.
It looks like the clutch I bought is the later style and has the newer improvements...longer style 3/4" 18TPI nut and larger clutch springs, etc.

The "How To Restore" book writes:
"The third and final nut #2275-38 is 2-51/64" in length and can be quickly identified by it's copper coating. (copper plated to make the nut stand out from the others).

The 2-51/64" tube nut that I have is just the normal colour of heat treatment, (silver and mottled black) and has never been copper plated.
I rang the store this morning to order one of these longer style nuts, and they have one NOS nut that is copper coated and another NOS nut that is not copper coated. It would seem that some were copper plated and some not.

Thanks for the information. I will forge on with the assembly when I get the new nut.
Regards Steve

[Lonnie]

Who's winning, you or the clutch?

[Steve Little]

Hi Lonnie.
I think all will be well when I get the new nut because all the parts are in very nice condition.
I had to order the tube nut from another State so the parts should arrive today or tomorrow.
There seems to be an extra fibre plate in this setup that I have. There are 3 fat fibre plates and one thin fibre plate #2481-36.
Was this thin plate dropped from the assembly in favour of the 3 fatter plates?
Regards Steve