4X4 vibration @ 45mph and up

[Big92F150]

check ujoints...i dont know if had been mentioned

But i grenaded my rear ujoint the other day (my own fault) but after i replaced it all my vibrations went away...it was a cadillac again...

i will have to check that. i had ujoint problems not to long ago but i dont think my mechanic replaced them or actually took a good look at them.