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bsa clutch hub


On many BSAs I have worked on, I have always found that the splined clutch centres,(see photo) and also the  engine sprockets will slide apart by hand, easily.
With my B44, they are both VERY tight.

The clutch took about 20 heavy hammer blows to get off.
The primary chain would not come off the engine sprocket, because of the closeness of the rear case casting.
The sprocket resisted all attempts to pull or hammer off.
I finally got the blowlamp on it, trying to avoid burning the chain. This was successful.

I have now polished the outside splines on the inner clutch centre, and used a dremel grinder to polish the splines
inside the outer part.
Now, the parts will slide together part way, then lock up.
It will take hammer blows to push fully in. I do not want to assemble like this.

How can this be???
Suggestions please.

Thinking ahead to reassembly (Im waiting for my crankshaft return from Alpha), I thought it would be
impossible to assemble the clutch body, on the shaft, then fit the rollers with grease, then have to hammer the
Centre on to its splines without letting the rollers fall out.
So, I have the clutch bod on the bench fit the rollers and grease, then press the centre onto the splines.
The assembly can then be fitted in place with the chain and engine sprocket all together.

I was lucky! The centre slid on with hand pressure only (well , a thump with my fist.)
I had tried the fit beforehand, at each of the six positions. None were successful.


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