Rear vibrations single cab 04 4x4 45mph+

Need help on how to fix this ujoints are good tires are balanced and rotated
HELP?!?!?

 

If it doesn't eventually go away as speed increases it probably is something like a u-joint or the center bearing. Just because you can't wiggle a U-Joint and find play in it doesn't mean it's not bad. They can get stiff also and vibrate just as bad as one with play in it. If it changes with throttle applied or when coasting you could be looking at a ring and pinion issue also.

 

Are you sure its the back? I had this vibration that was only 45+ish and it was a tie rod end

 

It's the rear for sure and it does smooth out around 67 mph

 

just keep it below 45 and above 67.problem solved