I dont know whats going on
 

so I have a mega cab 4x4 dually. Now my problem is at about 45-50 my thing shakes pretty hard. its not the death wobble I have experienced that before. I have the put new tires, ball joints, tie rods,and shocks. whats going on once I get above 45-50 she smooths out? anyone? and all tires have been rotated and balanced.

I had the same problem.
I am now running just balancing beads .
I find the factory rims are terrible for letting dirt build up in all the areas you can't wash right out .
I found you never got all dirt out from the inside area by the brake rotors so I would never have a completely balanced tire. I would get some build up out but never get it all.
Try it always it's still working awesome for me.