Well, from the sound of it when you get into the higher revs the trans. is slipping. And if you still have your foot in it and it trys to shift to OD, it may not be so good for the trans. I know the 4R's don't like WOT shifts into OD, and I would think the same goes for the AOD.
The bump may be a bad tire, out of balance tire, bad u-joint, etc... Check all of the rotating parts for strange wear and see what you find. Heck, it could even be a wheel bearing.
These are highly engineered precision vehicles, the first step in diagnosing the problem is to strike the suspected offending part sharply and repeatedly with a blunt object, then re-test.