compressing engine cush drive nut on B33?

[daveysprocket]

Re 1956 B33 engine
Please can you advise how to compress the spring enough to allow the threads of the nut to engage on the shaft? Mine has about 10mm to go.
Many thanks.
Dave

[DAVE BRADY]

Hi Dave,

Unless someone can say otherwise the nut should engage with the thread on the crank without having to compress the spring.  With the lobes of the cushdrive fully together the nut should start and turn several times by hand before needing a spanner.  Is it a new spring?

Dave.

[daveysprocket]

Hi Dave, thanks for that; mmmm! sounds like something is amiss here then. I had to arrange a lever (quite a long one) to press the nut in while my dear wife turned the engine over to spin the crank. It took a few goes to get the thread to catch squarely.
Something I'll have to look into.
Thanks again and kind regards.
Dave

[Mark N]

My M21 spring was difficult to compress. I wound mine up in a vice for a while, took it out and put it on before it realised what i had done. It worked for me, but i can't really see why 

[Pete C]

I always have to fight with these, trying to compress the spring enought to get the nut to thread on squarely. You could try compressing the spring in a vice and use wire or cable ties to keep it compressed while you fit the nut. Removing the ties/wire can be a bugger as well.

[MICKREEVES]

I used to do it by pushing the nut in against the spring, using some large, heavy flat object, which I could hold in with my chest pressed against.
Mick

[daveysprocket]

Cheers Mick, you must have experienced similar to me and had to be innovative and come up with a solution to the problem.
My situation was made even more difficult, having fitted a new clutch, when it became necessary to align the chain/sprockets by packing out the front sprocket.

[DAVE BRADY]

I think that there could be some different specs. for different engines.  I do not have anything with part numbers for this spring so cannot say for certain.  On a couple of A10s I have never needed a lever and even a new spring was just about engaging with the threads and could be pushed in by hand enough to start screwing on. 

Dave.

[chaz]

My only experiences on this are with square fours, didn't seem a problem apart from doing up. Drags new nuts are made of metric hex steel, the mm socket wont fit down inside the cup washer so I ended up making new ones on the lathe and cnc milling the hex to brit size.

[daveysprocket]

Thanks for your comments guys. I will have to investigate further re correct components, i.e. spring too long or nut to short.
Otherwise it will be a matter of making a good tool to compress with. My last effort was all a bit Heath Robinson and risked damaging the threads.
Regards
Dave
p.s. It is now running fine, so all being well we will be off on the Dragon Rally in two weeks.