I had my F150 2012 FX4 Eco in the shop three times for a clicking noise in the rearend when shifting from p-r or r-d. The mechanic was told by the engineers at Ford to tighten the pinion nut 1/16 of a turn. Less than 300 miles after getting the truck out of the shop I broke my pinion while going down the highway at 70 mph. Made nice sparks and a cloud of smoke from the back of the truck at 0430 in the a.m.
Long story short the dealer changed the rearend/driveshaft. The truck has 14,000 miles on it and two oild changes later a new rearend.
Oredered a new 2013 FX4 Eco same as the 2012 except the color, have to get Ruby red no more candy red offered for 2013. I feel as Ford broke it they can keep it.