Ford: 2005 F150 4x4 supercrew rear differential

Question
Hi Brian,
Here is the problem I was backing into my driveway with a very small trailer. Total weight load and trailer max 400 lbs. My driveway is at an pretty good incline say 20°. (guessing) When I was backing up the driverside rear wheel was on grass/dirt and spun a little. I parked the truck, removed the trailer. The truck sat for say an hour or so on this incline. When I finally went to move it the same rear wheel would skip, not roll smoothly.
I pulled on to the street turning left and the wheel rolled like the abs was ingaged. I pulled fully on the road and you could see where the wheel rolled with high resistance. (skid mark). I took another left and the same thing happened, it wasn't until the truck was going straight down the road that the wheel was rolling like normal. Any idea? Is it abs, or the gears in the differential?? the truck gets really poor mileage also.

Answer
Hi , first question . Did you apply the parking brake at all during this ? These trucks were known for the emergency brake sticking. You can tell if you look under the truck on the side that was dragging and see where the cable for the E-brake goes in. The return spring on the cable will look collapsed  in comparison to the other side if you look at the two of them