1946 B31 clutch options

[Farmer Jon]

Has anyone upgraded to either the triumph clutch or aftermarket dry clutch on a 46-48 B31. It seems the taper is different on the transmission shaft?  I have two clutches that don't look like they will add up to one.  Suggestions please

[Pete C]

as far as I know you cannot use an alternative clutch on the 46-48 gearbox. You are stuck with the 6 spring due to the shorter mainshaft issue.

It is however possible to get the 6 spring to work quite satisfactorily if care is taken in the set-up and component choice.

I have a B33 with the same issue and I admit I would rather have a choice of clutches ...but at least I have a lovely bike anyway 

[Farmer Jon]

Thanks for the reply ... So is. just the trans shaft different length?  Is the taper and sleeve different.  What else in the clutch is unique to 46 / 48.  Thanks for the help

[Pete Gill]

Hi All
I have been doing some work on my 1949 B31
I'm not sure which gearbox i have
Can any of you identify?
Pete

[Pete C]

that is the later "standard" box, not the 46-48 variety

this is the 46-48 on my B33


sorry the picture is so big, you'll have to scroll accross to the gearbox 

[Pete C]

and I think the clutch is just the standard 6 spring but just the mainshaft is shorter, not 100% sure tho. There are certainly more informed members who can provide the info.

[JulianS]

The 46-48 has a different centre (or sleeve) with an internal  thread for the puller and the mainshaft nut is different.

[Pete Gill]

Thank you Julian and Pete

[cdsdorset]

Your box is a later one. Easy to tell the earlier box has the Speedo drive coming out of the nearside at the bottom.
The early gearbox has a shorter shaft with a different taper the hub for them is virtually unobtainable. Last time I searched I found one in Australia.