Clutch Fitting

[Andy M]

I'm rebuilding my A7 Shooting Star at the moment. It's a 1960 model with a 4-spring clutch.

How tight should the clutch centre be? I'm finding that when I tighten the centre nut, the clutch is getting pushed back to the point where the sprocket is fouling the chaincase. I'm not sure if I'm pushing the clutch on to far or whether I have a problem with mis-alignment of engine and gearbox.

Anyone else had this problem?

Cheers,
Andy

[chaterlea25]

Hi Andy,
THere are several topics on this subject if you search the forum
You may have the wrong clutch centre? Is it split? sometimes they crack at the edge of the keyway
The centre nut needs to be really tight, I go to 75ft lbs

Have you bolted the inner case to the frame at the back? theres a spacer required?
Have you the correct spacer between the crankcase and primary?
Is the sliding plate turned the correct way?

HTH
John O R

[bsa-bill]

Hi Andy and John
I just popped into check what the torque setting for the clutch centre nut should be so thanks John

Andy I'm busy putting my clutch on now.
Forgive the obvious question ( but I had to remind myself when I came to it), but have you got the tab at the back of the primary inner case 'behind' the frame?
next what kind of clutch centre do you have is it with or without cush rubbers, I had no end of trouble with a cush drive centre, the centre nut would become threadbound before the centre was  tight, similar problem to yours although mine wasn't catching the inner case.
I suspected the adaptor was going too far up the taper but it turned out to be the clutch centre, I scrapped it and bought a non cush one and it went on without trouble

[BSA_54A10]

The position of the clutch is determined by the clutch hub on the main shaft.
If you are reusing your old parts then you have either left something out or the main shaft is moving.
I have clouted the hub puller hard enough with a mash hammer ( brickies hammer to some ) to break the gearbox housing where the bearing retainer is.
Now that I am older and have more toys I use a rattle gun on the clutch hubs which just about always pop straight off thus avoiding an expensive repair to the box.

[Andy M]

Bill,

I've got the rear tab of the primary chaincase 'in front' of the frame i.e. to the left or outside of the frame tubes. Should it be the other side - that might explain my problem?

I don't think I've forgotten any parts - I've been through the parts book and everything seems to be present and correct.

Oh and it doesn't have cush drive rubbers.
Thanks for the quick replies - first post on here and I don't expect so much feedback on a Sunday afternoon - you lot should be out on your bikes!!

Andy

[bsa-bill]

Yes the tab goes behind the frame ( inside ), and a spacer between the  chaincase and the frame if needed, sometimes a washer or two do just fine.

And yes I should be riding, if I'd got everything right first time around I might be, it is raining though

[chaterlea25]

Hi All,
Andy, that'll be your problem alright!!! Had you put in the 2 bolts at the rear of the crank sprocket, There would have been a gap at this point???

Bill, my torque value is guess work on my behalf, I based it on the 65ft/lbs recommended for the cush drive nut
when I tightened up the clutch to 65 I felt it could do with a bit more so went to 75 ft/lbs
A lot of times I tighten them up with a fork tube over one end of the T bar till I grunt 
Cheers
John O R

[bsa-bill]

Hi John
I couldn't get 75, got new brake shoes in the rear brake and they won't hold the wheel at anywhere near that torque. got it good and tight though.
Got the same problem with the crank nut (SRM), so will leave it at the moment and get a bit more on it when the wheel is on the ground.

[Andy M]

Yup that was my problem. Move the case to the other side of the frame and now the clutch is running sweetly.

Thanks for you help gents.

Andy

[chaterlea25]

Hi Bill,
If you have a couple of old clutch plates, get a plain and a friction
align them and drill a couple of holes  to bolt them together 2 bolts on one side, a couple of spacers and a length of flat
iron drilled to go onto the 2 bolts on the same side
This will lock the clutch and crank when the flat bar goes against the footrest bar or the work bench
I have a skipfull of old plates if you need some

HTH
John O R

[A10Boy]

I bought one of those drum clutch holders, it works very well.

SRM say 64ft/lbs and use loctite.

[bsa-bill]

I've got a clutch locking plate but it has no handle, jeez I never thought about using it with a handle against the footrest, it would lock the crank up too.
I never cease to wonder how the obvious can pass me by at times 
Well that's the first job on the agenda tomorrow - make handle

A10boy I had quite some job removing the SRM crank nut, it was the loctite, very good stuff and it was getting tighter the further it came, had to put a heat gun on it eventually, so not much chance of it slackening

[LJ.]

I never cease to wonder how the obvious can pass me by at times

I know exactly what your saying Bill... I've seen one of these home made clutch locking tools but never thought I could make one because I can't weld. John here mentions bolting one up, why did I not think of that ???? ????

I also will be making that very tool tomorrow with the handle too

[chaterlea25]

Hi All
Royalties are welcome in the form of beer vouchers

Glad to be of help
John O R