Flywheel vibration?

[Waterloo]

Find out if you have a solid clutch brake or a two piece. If a one piece, see if they will cut it out and replace with a two piece and see what it sounds like. My money is on the clutch brake. That is a helluva a lot cheaper than a new clutch, unless you need one? Then the rear structure needs to be done too, if you have an ISX, or you will wind up paying double when the rear structure is puking oil all over the place.