So I bought my 2014 XLT with 17K on it back in March of this year. The truck had the original tires on it and on the test drive has some front vibration like a tire was out of balance they agreed to fix the problem which turned into 4 new tires. Fast Forward 2500 miles later and the vibration is slowly coming back. I thought maybe I threw a weight so I stopped to have them re-balanced and tire shop said they are cupping real bad and was shocked they only had 2500 miles on them. So I took it to Ford they came back said it was the cheap tires nothing wrong with the truck. About a month ago I go find a deal on some low mileage FX4 take off's and I can tell the problem is still there, but not as bad. A month later it's full on. Ford still says no problem, it comes on about 45 mph and gets worse as you speed up. It feels like a warped rotor, but I'm not stopping.

 

Take it to a good independent alignment shop and get the whole front end checked.