Author Topic: b.s.a.c15 clutch ??  (Read 375 times)

Offline mossy

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b.s.a.c15 clutch ??
« on: November 20, 2017, 05:10:35 PM »
hi guys, this engine overhaul is still giving me loads of problems.i have began work on the clutch and having got the new cluth spring nuts I,ve found that they are fractionately smaller than than the studs on mine.it is clear that the clutch has been changed at some time as this is nothing like the c15 clutch seen in all the manuals etc. my chainwheel  has 40-3204 stamped on the back of it,and although it is still a 4 plate and  fits on the shaft/keyway o.k however there is a wobble/play so probably needs needs new rollers but I hav,nt a clue how to strip it  down any further.  I thought about re tapping the studs to fit my spring nuts but can,t get at them.i know its a long shot but if anyone recognises the number stamped on the back of it or knows what this clutch maybe off,then maybe I can progress further.any help would be appreciated,kind regards, steve.

Offline Rex

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Re: b.s.a.c15 clutch ??
« Reply #1 on: November 20, 2017, 06:42:48 PM »
That's the part number for a C15 chainwheel so no problem there.
Most have "wobble" so don't go buying new rollers on the strength of that little diagnosis, and I wouldn't worry about "retapping" anything as if your diagnosis is correct then the studs would need changing and they won't be able to be "retapped".
IF I was you I'd ascertain what thread and type of clutch nuts you need and buy some, closely followed by a manual and a clutch puller.

Offline mossy

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Re: b.s.a.c15 clutch ??
« Reply #2 on: November 20, 2017, 06:57:55 PM »
thanks rex,i,ll try that.(I already have both Haynes workshop manual and Rupert  ratio book along with clutch puller.

Offline Rex

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Re: b.s.a.c15 clutch ??
« Reply #3 on: November 21, 2017, 06:23:07 PM »
If you "haven't a clue how to strip it down further" then read the manual. ::)
Haynes aren't wonderful, but even that little book of words must detail how to remove the plates and use the puller, surely?

Offline mossy

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Re: b.s.a.c15 clutch ??
« Reply #4 on: November 22, 2017, 09:08:52 AM »
cheers mate, I have already pulled the clutch off and ,removed the plates,but my clutch doesn,t look anything like the books. the backplate with the studs maybe has been replaced at some time as this is what the clutch spring nuts screw onto. i still hav,nt found how to get into it and the books don,t help much !

Offline chaterlea25

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Re: b.s.a.c15 clutch ??
« Reply #5 on: November 22, 2017, 08:00:50 PM »
Hi Mossy
Can you post some photos?
One pic is worth a thousand words

John

Offline mossy

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Re: b.s.a.c15 clutch ??
« Reply #6 on: November 23, 2017, 09:17:10 AM »
thanks john i.ll get on it hopefully later today.regards steve

Offline mossy

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Re: b.s.a.c15 clutch ??
« Reply #7 on: November 24, 2017, 10:24:13 AM »
hi john, right, I,ve stared at it some more and read the manuals. I,ve removed the four countersunk screws and then it says prize off the retaining plate. that's the bit I,m stuck on . how the heck do I get the plate off? bearing in mind I don,t want to damage the studs.. I know its probably been on for 50+years but it feels like its welded on !

Offline iansoady

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Re: b.s.a.c15 clutch ??
« Reply #8 on: November 24, 2017, 02:00:22 PM »
That plate covers the shock absorber, which is a vane type thing with rubber buffers. It actually looks like a Triumph clutch to me* although I'm not sure why you feel you need to remove the plate. It only really needs to come off if you're replacing the rubbers (which can be tricky.....)

The studs will probably be riveted into the backplate.

I'd look for the correct clutch as the taper on this one may well be incorrect for your gearbox shaft.

*not being an expert on either C15 or Triumph clutches........

Ian
1952 Norton ES2
1962 Ariel Arrow
1982 Moto Guzzi V50

Offline Rex

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Re: b.s.a.c15 clutch ??
« Reply #9 on: November 24, 2017, 05:56:56 PM »
As Ian says, there's no need to remove this plate at this stage, but you should be able to screw in the clutch puller now and remove it.
I agree that it looks like a Triumph clutch (maybe that's why you can't use the puller?) but I've never heard of using a Triumph clutch on a C15/B40 before. I'm guessing the taper must be suitable as if not the clutch wouldn't be attached if not.
If I remember correctly the studs aren't riveted, but push through from the back and are prevented from turning by the square heads they have bearing on the rear boss of the chain wheel.

Offline chaterlea25

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Re: b.s.a.c15 clutch ??
« Reply #10 on: November 25, 2017, 12:49:52 AM »
Hi Mossy,
OK
So we need another photo of the rear view
Smaller resolution would help too

BSA and Triumph clutches look more or less the same in photos
The inner drum should revolve in the outer drum
It should push out easily from the back and drop the rollers everywhere   :o  ::)
Try an ordinary  1/4 x26tpi nut on the spring studs, if it fits ok then its the new spring nuts are the problem
Some of these type clutches the spring studs thread into the inner drum rear and are peened over at the back
These are one use only parts

John

Offline mossy

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Re: b.s.a.c15 clutch ??
« Reply #11 on: November 25, 2017, 05:29:27 PM »
rex, you keep saying about not being able to use the clutch puller, i can,  and have used the puller.i need to get this plate off, because my 1st problem is that the standard clutch spring nuts supplied don,t fit my studs so i think i,ve got to either retap the studs, which i can,t get to, or retap the nuts to fit my studs.either way i need to check both the rubbers and rollers,because the wobble or play is massive and while i,ve got it stripped down i,d like to remedy it. thanks for all the help and advice so far, cheers guys. i,ll also try and post another picture.

Offline iansoady

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Re: b.s.a.c15 clutch ??
« Reply #12 on: November 26, 2017, 10:38:56 AM »
When you say it wobbles, what exactly is wobbling? If it's the whole assembly on the gearbox shaft then it's probably the wrong taper.

Getting that plate off will not do anything as regards your puller. As John says the centre should just push out.
Ian
1952 Norton ES2
1962 Ariel Arrow
1982 Moto Guzzi V50

Offline Rex

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Re: b.s.a.c15 clutch ??
« Reply #13 on: November 26, 2017, 11:03:55 AM »
When you say it wobbles, what exactly is wobbling? If it's the whole assembly on the gearbox shaft then it's probably the wrong taper.

I'm assuming that this "wobble" is the normal play seen at the chainwheel when the plates and springs are removed. If the wobble was due to the wrong taper then he'd be able to lift off the assembly as the taper wouldn't have grabbed.
In the pics the clutch assembly (or most of it) is shown still fitted, so how have you used the puller?
If you had, you'd have all the bits off and laid out on the bench by now?

Offline R

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Re: b.s.a.c15 clutch ??
« Reply #14 on: November 27, 2017, 02:34:33 AM »
U guys need new glasses ?, I can see the mainshaft in the background  and clear through the clutch centre, which is obviously removed from its shaft !!

I think the OP is on about the clutch centre rocking on its bearings on the clutch backing plate.
This is normally not an issue - once all assembled, the movement is quite limited (?).
Get the little cover plate off, and see that all is well inside ?

Then concentrate on getting the clutch assembled and working.
Your jar of misc nuts should let you figure out what thread is on those spring studs,
maybe you need to then buy something to match if you don't have them ?
Modifying them is usually a bodgers path to trouble....
hopethishelps.