BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: nfraser103 on 04 May, 2021, 15:03

Title: A10 Semi unit clutch assembly problem
Post by: nfraser103 on 04 May, 2021, 15:03
Hi,

I am rebuilding a barn find A10 but cannot find any decent parts drawings to explain which spacer parts are missing from the rear of the clutch outer drum / bearing assembly.  On the pictures, you will see the steel spacer/washer that holds the roller bearings in place appears to fit against the thin plate which holds the oil seal in place.  When I assembled everything using these parts, the chain rubbed badly against the inner chain case and caused about 3 mm of damage around the casing, so obviously, it needs spacers to hold the outer drum away from the chain case housing.

Does anyone have a picture which might help me or can advise how thick the spacers should be??

Thank you
Title: Re: A10 Semi unit clutch assembly problem
Post by: DAVE BRADY on 04 May, 2021, 15:17
Hi,

In your box of clutch bits there should be what looks like a ring that is in two halves.  These go in the groove in the gearbox shaft and the clutch centre plate then sits against them and holds them in place.  Is that a flat washer in picture?  The side that goes inwards has a shallow chamfer and groove to fit over the split ring.  I will see if I have and illustration.

Dave.
Title: Re: A10 Semi unit clutch assembly problem
Post by: nfraser103 on 04 May, 2021, 15:32
Hi Dave,  Thanks so much for the quick help. There were quite a lot of parts missing or badly fitted, the clutch ring you kindly highlighted was / is missing..... If you are able to find a drawing, that would be great.  A previous owner did a lot of things to the bike....like welding the gear lever in place, welding footrests
in place etc etc.

Rgds

Neil
Title: Re: A10 Semi unit clutch assembly problem
Post by: DAVE BRADY on 04 May, 2021, 15:42
Hi,

Images of the spacer/disc
These parts should be available.

Dave.
Title: Re: A10 Semi unit clutch assembly problem
Post by: nfraser103 on 04 May, 2021, 15:47
Thanks Dave,

That is quite similar to the one I fitted, although the clutch ring is the missing item.....

Thank you
Title: Re: A10 Semi unit clutch assembly problem
Post by: DAVE BRADY on 04 May, 2021, 16:01
Hi,

I just had quick look for the 'main shaft split washer' and only degroot-bsa.nl comes up.  They have them at €6 and the thrust washer for €10.  As two new parts they should fit well rathe than a new bit in a worn bit.

Dave.

Title: Re: A10 Semi unit clutch assembly problem
Post by: nfraser103 on 04 May, 2021, 17:38
Hi Dave,

Thanks very much for this invaluable help

Have a good evening
Title: Re: A10 Semi unit clutch assembly problem
Post by: idie on 04 May, 2021, 18:27
I got a split ring for a friends A10 last year from Dragon Fly. It comes as a ring which you snap into two bits.