Hi Nigel,
The first thing you should check is that there is some free play in the clutch cable - if not, then the clutchplate may be holding up on the release bearing. If this is OK, the problem lies within the clutchplate itself or it's connection to the gearbox. The problem may be no worse than oil on the plate - in which case, a wash out with petrol may cure it. If the clutch has first generation asbestos free linings fitted, it may be suffering from dust build up on the clutch guide pins - usually resulting in erratic operation - both dragging and slipping. If the slipping only occurs after about 10 miles, and then clears up again when the engine has been allowed to cool a little, the problem is likely to be worn splines on the drive to the gearbox, biasing the plate one way against the flywheel (this usually only occurs after a high mileage).
Adjustment of the cable and washing an oil soaked plate can be done in situ, but any other work will entail separating the engine and gearbox.
The early asbestos free linings are usually a dark grey composite material that gives off quite a lot of dust - later linings are made of a woven material very much like the original Ferodo.
Unfortunately, there are few people specialising in Douglas repairs these days, so you may end up having to tackle this yourself.
If you do decide to take it on, come back onto this forum when you have a better idea of where the problem lies, I am sure you will get a lot of advice and assistance from the other members.
Regards,
Eddie.
