I have an 09 commander 3.7 all time 4x4, anytime I'm going at a constant speed and very slighty try to accelerate my front end starts to vibrate and feels/ sounds like I'm running over a rumble strip. It's only when trying to accelerate very easily. Once I get on it and it down shifts it fine..let's say I'm coming to a hill and I easily get on the gas and it doesn't down shift it will start shaking until it down shifts. It almost seems like a drivetrain issue but I have no idea. Seems to come from front passenger side.