I just saw your posted videos, It sounds something is loose and vibrates when pressure changes ( RPM goes from 2K+ down to 1.5K) , I would start to check for anything loose on the path of Air intake on Engine air filter/ housing, clamps, EGR, ... then move to turbo and exhaust pipe path
Also...
Hey Zach,
What is your milage ? how often you tow ? what do you tow? do you have a lift kit ?
There could be any of the following reasons (Amongst other reasons ):
1) Transmission oil needs to be changed - Check ZF website-
2) CV Joints
Is there any common circumestances (Transmission temp ? ...