Strange occasional rumbling through clutch pedal

[rufusw5]

I'm hoping someone can shed a little light on this, it doesn't happen very often so I don't want to start stripping yet but it'd be good to know if it's anything serious...

Every now and again, usually associated with braking hard and downshifting, I get this wierd rumbling through the clutch pedal, it makes no noise and feels like ABS kickback, then it goes away after a couple of gearchanges and everythings hunky dory...

It's a diesel Scudo van if that means anything.. I've never come accross anything like this before.. any idea's what it is or what it might be?

 

[DaveMcT]

It could be the clutch, but for now I'm suspicious of a gearbox bearing starting to fail. Check gearbox oil level. If blipping the throttle on down shifts (gives the 'box an easier time) solves it, you may have a pending problem in an input bearing.