2014 Ford F250 Super Duty, less than 60,000 miles. Recently developed periodic shake at about 50-60 MPH. We have spent over three weeks having trying to diagnose the problem. Multiples wheel balancing, moving rims/wheels from rear to front, new front U-joints, new tires. The problem still persist. Next looking at possible drive shaft balancing issues.Has anyone experienced this problem, any fix, suggestions.