I may have a problem with my 405 GLX TD clutch. Despite having covered 142,000 mostly motorway miles, the clutch is fine. It doesn't slip and although it bites fairly high (as can be expected) all is well. Unfortunately, every now and again when depressing the pedal it suddenly snaps down an extra inch or so with a clicky-clunky sort of noise which can be felt through the foot. If the pedal is brought up and depressed again everything is fine. It feels like a problem with the linkage to the pedal. Any ideas? KW