The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: bikerboy on 28.05. 2012 03:25

Title: A10 Plunger clutch
Post by: bikerboy on 28.05. 2012 03:25
Right forgive my bad memory but it is 30 years since I have touched my A10 and I am trying to put it back together

Clutch plates 5 metal, 5 cork but according to my parts book there is a 6th metal plate (slighter thicker) which goes in first.

Seems a bit odd to have metal to metal but I daresay somebody on here will know

Also after fitting the clutch basket and centre the primary chain seems ridiculously close to the chain case and there is a mark where this has obviously rubbed in the past. As its a fixed thrust with those silly little split collet things how can it rub on the chaincase ? There are no shims to the best of my knowledge ?

Thanks in advance
Title: Re: A10 Plunger clutch
Post by: Brian on 28.05. 2012 04:12
This one has come up before and if I remember correctly the parts book is wrong.

You should have 5 steel plates including the thick one that goes in first, ending up with a friction on the outside for the last plate which holds the cups and springs.

I've had quite a few of these apart and can not recall seeing one where the chain rubs on the inner case. You need to check the alignment from the front (engine) sprocket to the clutch wheel sprocket. The clutch thrust washer, the thing that goes ovet the split collects, comes in three different thicknesses, you may need a thicker one.
Title: Re: A10 Plunger clutch
Post by: bikerboy on 28.05. 2012 04:28
My parts books is wrong ? Damn I was not expecting that.

So you are saying that the last clutch plate in that the pressure plate clamps on is a cork plate ?

I was aware of the different thicknesses in the thrust washers but the difference is minimal and I dont think it will make a lot of difference regarding my problem.

I will try to put a straight edge on the chain to see where that takes me but I am concerned about it
Title: Re: A10 Plunger clutch
Post by: Brian on 28.05. 2012 04:47
Yes, you should have cork to friction.

Put the thick steel in first and the a cork etc until you end up with the pressure plate on the outside.

If your sprockets are a long way out of alignment you may have to look in the gearbox, could be the mainshaft is not coming through far enough.
Title: Re: A10 Plunger clutch
Post by: bikerboy on 30.05. 2012 06:10

Funny you should say about the main shaft not coming thru far enough because I am fairly convinced you are right but what the hell would cause that ?
Title: Re: A10 Plunger clutch
Post by: Brian on 30.05. 2012 06:19
Not really sure. The mainshaft is located in position by the kickstart ratchet assembly inside the outer cover, could be something wrong there.

Once you have checked the alignment of the engine and clutch sprockets then you will have a better idea of just where the problem is.
Title: Re: A10 Plunger clutch
Post by: duTch on 30.05. 2012 13:03
Hi B-boy,I had an issue when I swapped my mainshaft top sleeve gear with one with slightly better bushes,but was too tight in the bearing and wouldn't seat home  properly. I discovered a bit of distortion at the inner ends of the sprocket splines, so did a bit of very careful 'dremel-engineering', to enable the gear to push through the bearing enough. Do all gears select ok without (not so)funny noises? Regarding plates, can't recall what I may have posted, but in each of two baskets, like other folk I had only four friction plates each,and apart from not enough room can't see that 2 steel together would be detrimental,just less flex? Cheers, duTch'predictive text' is sabotaging me beware errors
Title: Re: A10 Plunger clutch
Post by: bikerboy on 01.06. 2012 03:04
Thanks Dutch for your input.

To be honest I have not ridden this particular bike in years and it needs a lot of work. I dont remember any problems the last time I used it but as I say it was a hell of a long time ago.