C: Clutch Twin clutch centralising plungers

[Chris Launders]

Should both plungers be touching their pins at the same time, I'm suffering from clutch slip and never tackled the clutch before apart from when it's had oil on it.
Anyway I've decided to have a good look at it and I've noticed that when turning the centre one way one plunger is touching its pin and the other is about 1/8" away, this changes over if I turn the centre the other way.
Chris.

 

[Bill Thomas]

Yes but only just, Most have some play,
But you don't want too much.

 

[Chris Launders]

Yes but only just, Most have some play,
But you don't want too much.

Thanks Bill
I've found this drawing in a previous thread.

 

[Bill Thomas]

I rode for many years with too much slack on one of my clutches,
Tends to let the shoes throw out and snag the drum
Stuart told us of a good repair ,
But I am not good at machining etc,
So I had some spare sleeves, Tubes, From another clutch, I cut down and fitted over the pins,
Where the plungers touch, just took up the slack,
Good cheap mod' !.

 

[greg brillus]

Chris the plunger ends should kiss the pins.......the wear tends to be mostly on one shoe more than the other.......if you rock the shoes, the ends of the shoes should be square to one another as best you can........this will show the plunger/pin with the most end play........there are several ways to fix this........probably the easiest is to simply add a small amount of weld to the end of the plunger, then dress it off nicely and test it back in possition untill you get the best result.......obviously this needs to be done with the plunger out of the shoe lest you cook the internal springs which probably should be replaced anyway.........with less play you can drill the recess in the shoe plunger bore a mm or so, using a drill and either a tube spacer to limit the drill travel.......or wrap a length of tape around the drill if you are careful this does work........I have had longer plungers made to fix this, but I've run out of them for now........all good fun........Cheers.

 

[Chris Launders]

I have a bit of oil on the drum which accounts for the slipping.
When I turned the carrier forwards the shoes lie parallel to the drum and I had about .080 between the C7/1 shoe plunger and it's pin, this I have now reduced quite a lot but I'm still working on it, it also explains why my clutch has always rattled so much.

 

[Gene Nehring]

Spring tension in the shoes themselves is often overlooked. Some threads here mention the Roy cross jig based on factory jig used to check tension is correct.

 

[bmetcalf]

https://www.vincentownersclub.co.uk/threads/vincent-twin-clutch.7752/page-2#post-65646

 

[Bill Thomas]

I have a bit of oil on the drum which accounts for the slipping.
When I turned the carrier forwards the shoes lie parallel to the drum and I had about .080 between the C7/1 shoe plunger and it's pin, this I have now reduced quite a lot but I'm still working on it, it also explains why my clutch has always rattled so much.

I think we need about 25 thou gap between the Shoe linings and the drum,
For a free clutch ?.

 

[BigEd]

I have a bit of oil on the drum which accounts for the slipping.
When I turned the carrier forwards the shoes lie parallel to the drum and I had about .080 between the C7/1 shoe plunger and it's pin, this I have now reduced quite a lot but I'm still working on it, it also explains why my clutch has always rattled so much.

It goes without saying that oil in the drum may be the cause of slip in this case. In my experience, the plunger pressure can also have an effect. When pulling away the pilot clutch pushes out the C7 shoe to transmit the power. The plunger spring pressure dictates how rapidly the shoe is pushed into engagement with the clutch drum. If there is not enough pressure the shoe engages rapidly and is almost certainly what causes the snatchy clutch that some people complain of. Conversely, if you screw in the C7 shoe spring adjuster too far you will get clutch slip.