A friend had another friend lift his 2014 F-150 two and a half inches. When it go it back, it was grinding, but only when you turn all the way to the left. Two shops looked at it and couldn't see any grinding from the tire or wheel. It was actually shifting the 4WD on one side when you turn left! Think of it like driving on asphalt in a tight circle while the 4x4 shift is in progress...grind city! It was a vacuum leak. Ford... You'll see the 12 foot long vacuum line tour and how the 4wd auto hub system works on the F-150 trucks. The leak wasn't obvious, but I found it and the dealership had the replacement vacuum line kit in stock! The vacuum kit part number is in the video at about the the 5:00 minute mark.