Author Topic: A7 6 spring clutch  (Read 3899 times)

Offline pjm01

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A7 6 spring clutch
« on: 31.08. 2013 15:00 »
The bike's a 1969 A7 Shooting Star (near Ipswich/Suffolk) and the 6 spring clutch has been problematical for the year I have owned the bike.(studs pulling out of the centre). After 2 attempts at welding which lasted a 100 miles or so and latterly, very poor quality replacement parts I have 'given up' and ordered a '4 spring conversion' from a respected supplier of BSA parts. Dismantling of the orig. clutch is well under way and only the (clutch chainwheel + clutch backpate + clutch centre) remain to be removed ..... but they will not shift. Is there a 'trick I'm missing' here as Haynes manual suggests the clutch chainwheel should just pull off and the clutch centre should remove after 'careful work with hammer and punch'. Obviously this last instruction is open to interpretation but I assume it does not mean 'beat the living daylights out of it'. In any case the chainwheel needs to come off first and it won't budge. Any advice gratefully received ...... Peter M

Online bsa-bill

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Re: A7 6 spring clutch
« Reply #1 on: 31.08. 2013 16:11 »
Hi Peter
no mention in your mail of a puller?
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline fido

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Re: A7 6 spring clutch
« Reply #2 on: 31.08. 2013 16:18 »
I don't understand why the chainwheel won't come off if the plates and chain are off. It just runs on a ballrace bearing and should just fall off. As mentioned, a puller is the best tool for the centre fitting. I assume your bike is '59, not '69!

Offline pjm01

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Re: A7 6 spring clutch
« Reply #3 on: 31.08. 2013 18:59 »
Sorry for my typo .... yes it's a '59 (quite right)

Will try pulling harder on the chainwheel ( I have removed the chain) ....

Puller ..... now there is a thought .... I'm aware there is a special one for the 4 spring clutch centre but didn't know there is one for the 6 spring centre.

Thanks for your suggestions.

Peter M


Offline fido

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Re: A7 6 spring clutch
« Reply #4 on: 31.08. 2013 19:03 »
You don't need a special BSA tool, just a fairly light duty puller with thin enough hooks to go round the clutch centre.

Offline pjm01

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Re: A7 6 spring clutch
« Reply #5 on: 02.09. 2013 12:29 »
Have made progress and the 'clutch chainwheel + backplate' are now off. The chainwheel plus the double row of ball bearings did not come off easily and needed some persuasion (forgive me, I'm not an engineer and doing this job with a spanner in one hand and the Haynes manual in t'other).
The 'immovable' clutch centre' (or clutch sleeve collar as it's called in my BSA Spares list) is on the other way round, ie wings inwards, to that shown by Haynes (and the spares list for that matter).... as it is keyed AND sits on a taper I assume the illustrations are wrong ???
Shall need to obtain a puller to aid removal.
I had assumed from the exploded diagrams thar the 'clutch push rod' simply pulls out (from the primary chaincase side) but of course mine slides out approx 1/2 inch and then won't come any further (locks solid) ...... why does everything 'resist' ? Do I pull harder or might there be a burr on the gearbox end which needs 'dressing' ?
Thanks in anticipation
Peter M

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Re: A7 6 spring clutch
« Reply #6 on: 02.09. 2013 13:11 »
Quote
might there be a burr on the gearbox end which needs 'dressing' ?

Sounds like a good call Peter, if not hardened the ends will spread.
it will come out of the gearbox end, not a big job to remove the gearbox cover or if that sounds daunting the adjuster on the end of the clutch lever ( on gearbox) can be removed ( don't drop it in the gearbox or you will have to remove the cover) and then the pushrod can be drawn out through the hole left buy the adjuster
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline trevinoz

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Re: A7 6 spring clutch
« Reply #7 on: 02.09. 2013 22:24 »
The clutch sleeve should have an external thread to which the puller body screws, Peter.
It seems as though someone has fitted an unhardened pushrod so do as Bill suggests.

Trev.

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Re: A7 6 spring clutch
« Reply #8 on: 03.09. 2013 12:36 »
Hi Peter , I think I have the puller you require and as my ( personal ) disgust/hatred with 6 spring clutches is well documented ,I can't understand why!! however if it would help you remove said piece of crap I will gladly donate it to you to help you retain your sanity which must have been stretched to the limit with the thing . Seriously send me a message with details and I'll get it to you regards BobH.
" rules are made for the guidance of wise men and the blind obediance of fools"
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Offline pjm01

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Re: A7 6 spring clutch
« Reply #9 on: 03.09. 2013 12:50 »
That's a brilliant offer TOPDAD and I very much apprecioate it BUT I have ordered one which is in the post to me as we speak ...... anxious to get the job done.
Peter M

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Re: A7 6 spring clutch
« Reply #10 on: 03.09. 2013 12:55 »
No probs Peter, if anything changes let me know and I'll post asap,BobH.
" rules are made for the guidance of wise men and the blind obediance of fools"
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Offline pjm01

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Re: A7 6 spring clutch
« Reply #11 on: 03.09. 2013 12:59 »
Pushrod came out easily from the gearbox end and it's now clear why it would not pull through t'other way. Pushrod end is 'belled out with a semi-circular depression' in the middle, captive ball on end of the 'clutch adjuster screw' locates and bears on the aforementioned depression. The 'belling out + depression' look to have been manufactured and not caused by long term wear. Peter M

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Re: A7 6 spring clutch
« Reply #12 on: 03.09. 2013 14:23 »
Quote
The 'belling out + depression' look to have been manufactured

have'nt seen millions of them but all the ones I've seen are dead straight
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline pjm01

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Re: A7 6 spring clutch
« Reply #13 on: 03.09. 2013 14:58 »
2 piccys attached I hope showing each end of the pushrod .......

Offline pjm01

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Re: A7 6 spring clutch
« Reply #14 on: 03.09. 2013 15:04 »
This is the gearbox end.
Pushrod is 294 mm long
Peter M