Ford Superduty Death Wobble fix

Yes this is where is was going as well. The Super Duty's have lockers on the front hubs that allow you to disconnect the front axles so they don't turn while driving. Perhaps you have yours locked in manual mode and they're constantly turning while driving even while your in 2 wheel drive.

Just went out and looked, the hubs are in auto at the three o'clock position. I have never operated the manual hubs before today when rotated one to locked just to be certain it really was in auto. Turned a lot easier than I recall a friends old Bronco did.

This truck does have lockers which I almost never use and there are warnings on the dash display if the locker is engaged.