C: Clutch Clutch Slip

[Freebird]

Hi everyone, this is my first post having only owned my 1950 Rapide for a few weeks.

Bob Collins suggested I post my query here and said that if I provide tea and better still, scones I will be inundated with cheerful members banging on my front door. Just in case that’s true, I am in Merstham Surrey..

After going right through the bike and fitting new tyres, I took it for its maiden voyage yesterday but the clutch was slipping badly. Today I stripped it down to find oil had contaminated the drum and shoes via the big rubber seal at the back.
That I can fix without much problem, but what has confused me is that the shoes don’t even touch the drum at full deflection under hand pressure. It all seems to be assembled correctly so I at a bit of a loss.

 

[Marcus Bowden]

Stopping the oil is the first thing, the big seal at the back of the primary case is an easy fix just go to a bearing store and order a 70 x 90 x10mm seal plus a 15/16 ""O" ring 2mm section then take take your shore carrier to a mate who has a machine shop and get him to put a taper or chamfer on the inside of the spline part that is up against the gearbox, slip the "O" onto spline shaft and put the carrier back in so it hardens up against the "O" ring saves putting a sealing compound on the splines.
The plungers in the shoes you should just be able to push them in with your thumb, reassemble getting the plate lifting squarely from the friction plate and try. There is another seal PD 25 but that is inside the primary cover in the chain wheel but that requires the cove to come off then nock out the bronze bush at the back of the chain wheel gently and replace the seal PD 25 can't remember the size as you could order one when at the bearing shop. Waiting for your next question.
bananaman.

 

[fogrider]

From the photo's, those linings look way too thin to me. The instruction sheets say check for a minimum of .025" clearance to the drum. New linings anyway if they're soaked in oil .
Regards all....

 

[delboy]

Linings look like they might be old "Duron". In which case they will clean and rough up with glasspaper and work again. The linings appear to be contacting fully on the drum
Unless the drum has been skimmed really, really, oversize the gap twixt linings and drum should work okay.
As Marcus says, plungers and springs in shoes to look at. Often springs are broken/coilbound. [Carefully cut away lining to expose C12 plugs and so replace springs]
Follow the diagram in the riders handbook to show the correct assembly of shoes/carrier.
That's the short version!
Use search for Stuart Spalding's earlier postings on the clutch, that should help immensely.
regards,
delboy.

 

[Freebird]

Thanks for all of the replies, what I was missing when I said the shoes don't contact the drum was the need to compress the spring loaded plungers. You learn something new every day.

delboy - I have tried to find Stuart Spalding's post without success, can you put up a link please?

Cheers

Glen

 

[delboy]

Sorry, I don't remember where, and linking is beyond my computing skills.
It's possible Stu' wrote it in MPH rather than here?
Also possible my brain cell malfunctioned.
delboy.

 

[Simon Dinsdale]

Glen
He goes under Stu Spalding and doing a quick search here is everything Stu had commented about clutches. Some posts will be more relevent than others.

Search results for query: clutch

www.vincentownersclub.co.uk

Simon

 

[Freebird]

A quick update chaps.

I bought a 70 x 90 x10mm seal as suggested above, but it feels too big to fit the recess. I think the OD should be 3 1/2” which is 1.1mm smaller. I will order one from the VoC spares company along with a new primary chain tensioner as mine is quite heavily grooved.

 

[timetraveller]

The tensoners do groove until the rollers can touch the surface. Check whether you need a tensioner or not.

 

[delboy]

I think Marcus has led you up the garden path.
My notebook says, the large clutch seal should be 2.75" x 3.5" x 0.375". The type with a rubber covered outer diameter. Get a double lip version if you can.
regards,
delboy.