Wierd vibration...
If I'm driving down the highway in OD at say 60 or 65, below 2k rpm (2.73 gears), the car is nice and smooth.
But if I take it out of OD so the rpm's rise, I get this bad driveline vibration. It also does it if I floor it at highway speed, to go from say 60-90mph, as I go through 70's into 80's, I can feel it again.
When driving non-aggressively, I never feel it.
Any idea what it could be?
Thanks!

