Ford F350 front end problems

I have a 2000 Ford F350 4x4 Dually 7.3 diesel with 90000 miles. It would shake violently when hitting a bump make horrible clanging clattering noises and you could feel it rubbing thru the floorboard. It started out small but escalated on a 500 mile trip home. We have replaced the ball joints, stabalizer bar, 1 wheel berring, tires, had it balanced and aligned. When the lock out was locked, it made a horribly loud grinding noise that sounded like it was going to lock up the entire wheel. We took out the lockout (the same wheel that we put a new wheel berring on) and tried using the other wheels lock out, thinking it was a bad lock out. No luck! I have had this truck to 3 mechanics and I am only sinking more money into it without resolution. What do I do next? Is there any place online to get a picture diagram of the assembly of the front axel and the parts associated with our problem. Also a u shaped piece on the pass side moves freely when the lock out is not in & the driver side doesn't move. We were told that was normal while the lockout were not in. Is that correct?