I have a 2004 F250 FX4 85k miles that vibrates at 43mph +/- and at around 57+/-. No noises, no increase with speed, it is at very specific speeds and feels like its in the seat of my pants, steering wheel is stable. I have rotated and balanced the tires at a minimum of 3 times at NTB. I replaced my shocks and the tires look good. I have read a few things about u-joints, does anyone have any suggestions or ideas on what could be causing this?
Thanks for any help!
Thanks for any help!