describe shaky. it could be a lose mount or bolt somewhere. I have a loose mount and it is only noticeable in park with the engine idling. its definitely not the tranny or engine. if I jump in the drivers seat really fast or shake the cab I can hear the same sound.

so try that first and make sure you don't have a shot suspension part or a loose bracket. never take your truck to mechanic unless you or a friend has known them for 20+ years. " its a dodge , they're plagued with problems". yeah no. not when taken care of right.

 

by shaky I mean it vibrates slightly more than before while idling. yeah, I don't trust mechanics too much either but I had to get a second opinion before dropping the transmission.

 

dropping the pan and taking a good look in the fluid and then the filter and solenoid will allow you to diagnose if your tranny is shot 99% of the time. that's all you really need to do.