Tapping noise in tranny?

[2003TangGT]

I have a 2003 Mustang GT. I have a manual tranmission and when the car is in neutral there is a chattering which goes to a continued tapping noise after a few seconds in the transmission. I just recently got my throw-out bearing. It's not making a sqeaky noise it sounds more like a tapping noise u would hear in the engine from valve lash. Any ideas? Is this signs of major problems with my tranny?

[Herbstang]

Clutch disengage = chatter. Clutch engage = no noise ?? A worn pilot bushing can cause chatter