clutch main shaft output nut

[Guy Wilson]

Does anyone know the thread size and pitch for the nut that goes on the end of the gearbox main-shaft that the clutch mounts onto? The nut size appears to be 1/2''
I'm trying to resist taking the gearbox out again and carrying it down to my local nut and bolt supplier. Things are not always that straight forward in Kenya

[bsa-bill]

At higher sizes Cycle thread can be 26 or 20 TPI, although I thought the 20tpi started at 7/8 I could be wrong though

[Goldy]

I have just looked at my spare and it,s  5/8" diameter 20 tpi.                                                                                                                 
             Bill  -      I think that the 20 tpi starts at 7/16".

[bsa-bill]

ah sorry guys my 7/8ths was meant to be 7/16ths, I have a die I bought for the crankshaft end and it 3/4 and 20tpi, ~IIRC the through bar for the footrests come in either 20 or 26 tpi

[trevinoz]

Not much use going to the local nut and bolt bloke, Guy.
Depending on which clutch you use determines the nut form.
If you are using the 4 spring clutch, the nut is a sleeve nut and has a thick washer with a recess machined in it.
Also a tab washer.

   Trev.

[Guy Wilson]

thanks Trev,
I'm going to take some photos and post them. What you're describing sounds like what I have already, a nut with a large sleeve and a recess machined in the rear of it. It didn't seem to tighten on to shaft far enough to be correct. It sounds like I may have bits from both clutches mixed up. It was in a big box of bits after all....
Guy

[bsa-bill]

Guy you might well have wrong bits, I put a Triumph 4 spring clutch on My RGF and had a lot of hassle getting the right combination of nut and Washer, some where supplied with nuts that the sleeve part would not go through the washer, others as you say would not get thread bound before the clutch centre was tight, even some of the really good firms sent me wrong stuff, I did eventually get it sorted.
unfortunately I have the cover on the primary case on now so can't give you any pics that might help, perhaps someone else can

[Guy Wilson]

Attached are a few photos of the clutch and the output shaft. The thread is BSF I've figured out.
The 'original' nut is how Trev's described it should be. The output shaft has about 15mm of thread sticking out. The 'original' nut won't screw on beyond about 5mm. I'm assuming its not the correct nut now. I'd planned to put a large washer and a standard nut. Am I missing something? Does the recess around the clutch centre need a locating washer or shim?

[Guy Wilson]

I think I figured it out. I have the wrong nut as this section from the 'Haynes' Manual seems to suggest

[A10Boy]

Yes
That's more like it!

[Beezageezauk]

Hi Guy,

FYI...the part numbers for the items you need are as follows:-

Mainshaft end nut     42-3267
Washer                   42-3237
Locking tab washer   42-3236

Beezageezauk.

[Guy Wilson]

Thanks for the part numbers. Does anyone know a place where I can order them from, preferably in the UK?
Alternatively, I was considering machining an inner sleeve and using a conventional nut and large washer. Does the proper nut tighten up against the inner basket of the clutch or does it tighten against the sleeve on the output shaft? Does that make sense?
Basically, does the inner basket need to be tightened or just held against the inner sleeve? I'm confusing myself now....
Thanks for all your help so far. I'm definitely making progress where previously i wasn't!
Guy

[Beezageezauk]

Hi again Guy,

I would suggest that you got the replacement parts rather than trying to make them yourself.  For A7 and A10 stuff I tend to use Lightning Spares, mainly because the owner of the shop knows these models inside out after covering many thousands of miles on an A10.

Check the website out at www.lightning-spares.co.uk

Other UK suppliers are Draganfly      www.dranAnfly.co.uk    and C&D Autos. Their Email address is canddautos@gmx.co.uk

Regarding your other question, I just tighten the thing up as far as I can.  Using a clutch locking tool helps.  I have an inner and an outer scrap clutch plate pop-riveted together for this job.  It works well.

Good luck.

Beezageezauk.

[Guy Wilson]

thanks Beezageezauk,
I'll give lightning a call,
Guy

[trevinoz]

Guy,
             I doubt that the thread is BSF. It is cycle.
The thick washer that you will get will have a recess that clears the mainshaft spline and allows the hub to be pulled up tight.
The nut that you have is for the 6 spring clutch.

  Trev.