I have a 2003 Cummins and its currently stuck on the side of the road. I have been hearing a bad noise which i had thought it may had been a exhaust leak. As i drove home from college it became progressively worse and then i came to a stop sign and a loud crack and bang below my feet and it then had no power to the wheels from the engine. It sounds terrible in park also and when turning on and turning off. Clanking and small banging. It will not go into gear. All guages show temps fine and it has oil and trans oil. Nothing is leaking. The noise seemed to be worse when i would slow down to an idle from about 30 miles per hour. Almost a buzzing sound. Then As i accelerated sound would dissapear then become louder as i got faster. Possible that the torque converter failed? I just recently had the transmission redone last fall. And nothing seemed odd about the shifts between gears. Need Help!

 

Probably the flex plate. Either call a wrecker or a friend with a trailer, the trans will need to come out either way.

 

I've been in a truck when the flex plate disentegrated, and it sounds a lot like you are describing. Once it does, no power gets transmitted through the torque converter.