I have an '08 Armada and have noticed the past 6-8 months a vibration coming from the tranny area (my best guess). It only happens when its in gear, as soon as its in neutral it goes away. it also cycles. starts small that increases then decreases. I was just curious if anyone else has had this problem. I had a similar issue in my old silverado and just replaced the traccy fluid and it went away but that had 150k+ miles and my armada only has 32k