well a lot happier this morning after i replaced the gearbox (what a doddle) when the post man delivered my new clutch nut to find loads of little bits of shiny case hardening in the bottom of my gearbox case,cleaned all the bearings in the crankcases and fitted the new/secondhand gearbox and took it for a ride gently to start with then as i usually ride on the edge of the redline no noises to report only a slight weap on the gearchange oil seal which i have ordered from my local bike shop.

just looked at my old gearbox and the bearing on the output shaft is very notchy.

thanks very much for your help and this box had done 38000klm so not too bad then.