So as of lately my truck will be in 4th gear cruising around 45-47 then rpms drop a bit and it starts to make a deep drown, and it kinda shakes when I give it gas to get it to go away it either does it when its cold, or sometimes when its a operation temp it doesn't pull any codes any ideas. I'm thinking it might have to be with the tranny

 

sounds like the tranny or the torque convertor.
or it could be the throttle speed sensor.