I have a 2014 f150 Fx4 5.0 6 speed auto super crew short bed 5.5. 98,000 miles I have a high frequency vibration I feel on my on the floor and in my seat at 60-65 kinda goes away at 70 and can feel it when letting off the pedal and disappears below 60mph. feels like a u joint the dealership replaced the u joint by the rear diff and no change they told me it’s the rear rotors are warped and that’s why it’s vibrating? I realize they are warped when I apply brakes but not when I’m cruising it shouldn’t vibrate nothing is sticking maybe the driveshaft is out of balance idk. I have checked my 4wd system everything is good there.
They should have replaced both rear drive shaft u joints and balanced the shaft after the replacements. Dealerships are famous for lousy work. Find a a specialty drive line shop and get it done correctly.
