Clutch shaft lockup problem

aljobo

Forum User
Non-VOC Member
I am building a Shadow I brought in from overseas in large lumps.
Assembling the clutch and tightening up the nut C20, at a point way before the nut is tight, the whole assembly locks up.
I have tried removing the seal 18/1 to see if its that that is causing the jam, but it makes no difference. It is as if there is no "shoulder" on the whole shaft assembly the clutch nut butts up against. The chamfered face of the rear part of the clutch shoe carrier looks flattened by being up against a face somewhere.
I have to say that I didn't remove the clutch sprocket, as the engine sprocket and primary drive chain were already in position, so I don't know what's going on behind it.
I would appreciate any advice, as this kind of thing can take ages to sort out by trial and error (mainly the latter).
Thanks in advance.
 

john998

Well Known and Active Forum User
VOC Member
Clutch

The most likely thing is that spacer PD21 is missing. This is the spacer that the oil seal runs on in the gearbox cover G2.
 

aljobo

Forum User
Non-VOC Member
Thanks John. The spacer is on the clutch sprocket side, I guess from the MO14 drawing. Does it prevent the assembly compressing? It did seem to me there was a gap behind the sprocket bush when I was trying to figure out the problem with a torch.
Ah well, another few hours dismantling and rebuilding!
 

john998

Well Known and Active Forum User
VOC Member
Clutch

The clutch carrier sleeve is nipped against this spacer, so without it things will lock up. The spacer is between the carrier and the inner of the output ball bearing. so is behind the clutch sprocket. John.
 

aljobo

Forum User
Non-VOC Member
OK John,
I'll be looking at it tomorrow or Saturday, so I'll keep you posted on how things work out.
Best regards,
Allan (from Greenock)
 

Hugo Myatt

Well Known and Active Forum User
VOC Member
Allen,
A rare mysterious and possible cause. At one time Tony Maughan made a special C18 seal which was an alloy spacer with an O ring on the outer circumference. This was thicker than the standard C18 and so required a special shortened C20. If this special C20 is used with the standard thickness C18 the whole lot will lock up.
Hugo
 

aljobo

Forum User
Non-VOC Member
Hello Hugo,
Thanks for the idea, and I think I read about this in the many disjointed bits of literature I now possess (the sure sign of a Vincent owner). But I think I found the culprit in today's dismantling. John (john998) is right - the PD21 spacer is indeed missing.
The upside is that it forced me to look at the other things that are dodgy. VinParts has another new order tonight!
New question on this subject - the inner ring on the output shaft bearing E91 turns on the shaft. Is this normal, or is something worn. If so is Loctite a solution, or...
Thanks, Allan
 

john998

Well Known and Active Forum User
VOC Member
Clutch

Hello,
The gear box input shaft is an slide fit in the bearing E91. So long as the clutch nut is tight it is not a problem. It should not be a loose fit though. I would not us loctite on it.
It may be worth thinking about having a look inside the gearbox at this stage, just in case any thing else is missing.
John.
 

petermb998

Well Known and Active Forum User
Non-VOC Member
clutch shaft lock up

Don't forget the spares company when buying spares.
if you are a member of the voc you could qualify for a discount for spares
which you do not from other suppliers.
 

aljobo

Forum User
Non-VOC Member
Hello John,
I had another look today and would say the bearing and shaft fit doesn't allow any radial play. Since the engine itself was completely rebuilt (new internals), I'm assuming that the gearbox was put together well. It's everything on either side of the crankcase itself that I'm systematically going through - timing side, gear selector/kickstart, and now primary drive side which weren't finished. What a learning process...
I'll keep you up to date with the issue when the parts arrive (Swiss Customs are water-tight and hold things back regularly to get the import tax)
Best regards,
Allan
 
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