Ahh,, the old Flex Damper .. It's a rubber / metal plate located in the bellhousing. Check the sight hole just behind the starter- you will have a small collection of rubber dust if it's going. It wil eventually start to disintegrate and you will start to smell burning rubber, maybe a litle smoke from under the hood.
Sit down. The part is about 600-750 bucks and a PITA to do- I had mine replaced a year ago and IIRC it was about 10 hours of labor.
