The problem with the original tool is that if the thread into the nut is worn, the bolt is even slightly bent or the spring has an uneven, non square 'set' then the nut will not be square to the thread when it is pulled down...That makes it nearly impossible to engage the very fine thread, particularly as spring pressure comes into the equation as well....
I made the first tool to the current pattern after struggling to do two different M20 clutches over a couple of days, in fact I made mine originally from an old piston and some turned parts as well...
There is no doubt that allowing the clutch nut to 'float' transforms the job and makes it very easy compared to the original tool....Ian
Hmmmm! Personally I think you will need to spin the nut freely to replace it....But as long as it works!:+1:
What size is the thread in your mainshaft nut? Looks bigger than 5/16 to me....Even Metric:scream:
Ron
Ron, it's 5/16 BSC. I went to my old Domi-Racer box, picked the one you suggested and it was correct. I'm sure you're right about spinning the nut. I expect it will be slow careful going making sure it's properly threaded.
It's an ugly as sin jury-rig and it's slow and awkward. When I have access to a lathe I'll make a ring. Who knows? Maybe my gasket set will take so long that'll I have that done before it arrives. Thanks to this forum, I understood the real trick would be taking the spring pressure off the nut and holding the spring in place once the nut was released. Cheers!
The 1946-58 list of BSA tools doesn't include this one, the more familiar clutch spring compressor tool is the one shown...
I've not seen this one before myself and wonder whether this is an aftermarket tool?...
BSA tools aren't usually marked with a description in this way, being identified by the part number and the illustration in the 'Service Tools' worksheet No.711....Ian
Yesterday I replaced the cleaned clutch plates with no issues. Piece of cake, really. My 5/16" bolt was a little bit shorter than ideal- I had to press the spring and nut in by hand to allow the long bolt to engage- but once that did I was able to hold the spring pressure away from the large nut enough to allow it to thread. It was surprisingly easy actually. As the large nut threaded down I simply had to periodically tighten the nut on the bolt a bit more to keep the spring pressure off.
It was made from a piece of soft steel strapping left over from a shelf unit. Bent on a vice and roughly shaped with a hacksaw. Very crude but it works.