Removing clutch/primary chain case

[Ducvelo]

Can anyone help me on removing the primary chain case cover. I need to get this right off to clean out and reseal (it's leaking badly), and see that the clutch needs to come off. Can you take that off without dissassmbling the clutch (eg simply undo that big nut in the centre and pull it off the splines), or do you need to take it all to pieces (as described in the books - seems a workup). Also, what's the best way of sealing the bottom of the chain case cover - do they often leak badly?
Thanks, Ducvelo

 

[ogrilp400]

You can undo the clutch nut via the centre plug but only a thin wall tube spanner or socket will fit through it and if the nut is tight like it should be then the tool will only spread. You seal the cover as you would any other oil bearing cavity.

 

[Len Matthews]

A leak from the Primary Chaincase joint is unusual and agreed, you can remove the Clutch assembly by first removing C26 Clutch Thrust Plug and unscrewing C20/1 Clutch Retaining Nut with a thin-walled box spanner or socket but ogrilp400 is quite right; it may very tight so the tool may not be strong enough. Then comes the question retightening adequately. Once the Clutch is out of the way you are still faced with removing the six C2 Clutch Drum Screws before the cover can be removed. Sounds like a lot of work to cure a leak but check the joint faces, fit a new gasket and all should be OK.

 

[bmetcalf]

If there is sealant on the internal splines of the shoe carrier, it will be very hard to pull it off the shaft, without dismantling the clutch.

 

[Vic Youel]

Every Vincent owner worth his salt should go through the process of dismembering the drive side. This exercise is likely to lead to other problems.... slipping or juddering clutch, oil leaks into the clutch .....bent spokes by the use of a tyre lever to stop the back wheel rotating instead of locking the brakes.....etc etc.

Why not change some main shaft bushes, oil seals and add the Maughan modifications to the main drive shock absorber whilst in the process. Sounds like you could benefit from some local expert help and mentoring.

Good luck

Vic

 

[timetraveller]

And while you are in there why not do the mod described below. These instructions were sent to Carl Hungness earlier today.
The modification is conceptually very simple and once it is done you will see why it works. All the work is done at the inside end of the C3, that is the opposite end to the shoes. The gearbox main shaft is 1” diameter and the outer diameter of the C3 is 1.25”. That means that the wall thickness of the C3 tube is 0.125, one eighth of an inch. The internal diameter of the ‘o ring has to be one inch to go over the shaft. If its section thickness was one eighth of an inch then there would be no shaft left so one needs an ‘o’ ring with a thickness of about one sixteenth of an inch, about 60 thou. I would get the ‘o’ ring first before your machinist chum starts to cut metal. Suppose that you do use a 60 thou section then he needs to cut the inside of the tube with an outer diameter of one and an eighth inch, that is the outer diameter of the ‘o’ ring, to a depth of about 45 thou. This will give a nip of 15 thou on the ‘o’ ring which is enough to make it act as a seal. In fact even 10 thou would do it and it is absolutely non critical. The reason to get the ‘o’ ring first is so that these dimensions can be changed if the ‘o’ ring has a different thickness to what I have used above. All that matters is that there is some of the outer diameter of the C3 shaft left and that the ‘o’ ring is nipped up to act as a seal.
Once this is done, oil just cannot get onto the splines and down into the clutch. In fact I even put a smear of grease on the splines and ‘o’ ring to ensure that it all comes apart if ever I need to work on it.
Best of luck with it

Norman

 

[Hugo Myatt]

I'm sure everyone knows but as no-one has mentioned it I thought I had better. Remember to slacken off the primary chain tensioner before attempting to remove the primary chaincase.

 

[ossie]

i have never slackened mine off in 45 years of owning it ,what for???

 

[Vic Youel]

I thought that too and did not have the nerve to question it. I suppose that it stops the clutch chain wheel slopping to one side as you withdraw the clutch assembly and potentially damaging the oil seal edge. But I never did it either.

 

[ET43]

Nope, because the PD10/1 is held in place by being spigoted into the primary chain case, there is a chance that when the case is removed, this might distort the recess that it fits in to in the crank case, and we wouldn't want that would we. If this does not happen, then you have probably been running the chain too slack.
Well, I know what I mean. ET43