What are the signs of a failing TC?

 

Chatter and vibrations. BUT 95% of the time its the tranny not the verter

 

Well, friday on my way to work I started getting a vibration that would be at it's worst when first accelerating. After I've reached highway speeds it would barely be noticeable. I have a Yank3000 and a FLP IV 4L65E both with about 2K miles. What can I do to narrow down the cause? Thanks.