Ok back to you everyone, had quite a few quotes for this flywheel change and this is the latest and it came from a reliable garage (if there is such a thing). The flywheel is solid and can not be changed, it is very highly unlikely to be damaged it just doesn't happen on solid flywheels they should last the life of the car, so they suggest booking in for a diagnostics check and start again. Anybody please does this sound feasible, at the moment the crunching sound is very rare but its driving me mad.
Robbie62