I have a 2011 Expedition EL with 175k miles on it, owned it since new. We used the 4WD a lot last winter with higher than normal snow in MT. In the spring I noticed some resistance and tight steering when driving on dry roads and it feels like the 4WD is engaged, even though the switch is in 2WD. I found some late season snow to test, and the front wheels do not spin in snow in 2WD, but they do spin with switch in 4WD as its supposed to. But with switch in 2WD the front drive shaft is still engaged and spins between the transfer case and front drive shaft. I believe when in 2WD the driveshaft is supposed to be stationary. I took it to my mechanic and he says all is fine, but I've driven it for 95% of its 175k miles and I still think the front drive shaft is engaged when it is in 2WD, but the hubs are just not engaged. I put my cell phone on the ground in video mode and drove over it in 2WD, 4WD high and 4WD low and the drive shaft turns in all modes. I'm thinking a bad actuator.