I have a 06 new holland TC 30. While brush chopping under load the tractor began having a loud chattering from the transmission/ clutch. This noise is when the tractor is in gear and in neutral. The sound resolves when the clutch is depressed. This sound does all of a sudden go away and returns on its own as well. Any ideas ? I would assume if it was a throw out bearing it would be worse when the clutch is depressed.