YES YES YES Man, I'll tell you, I hate when a dealer tells you "It's Normal." It is definately related to what GM refers to as their AWD system. My sister in law's Z71 is dead smooth in standard 2wd until you engage the AWD. Then it feels just like the full time AWD Denali. I am convinced that the vibrations, clunking and noise is related to the transfer case, and front axle. I have to say, my previous Expedition had a seamless AWD. GM has a ways to go.