1995 Chevy Blazer grinds and sond like helecoptor

Shakes or Wobbles problem
1995 Chevy Blazer 6 cyl Four Wheel Drive Automatic

my blazer arond town some times when I go and get down the road it start growling then sound like a helcoptor ive change rotors hub and breaks when I get on highway its got a vibration ive tryed every thing evenchanged the bearing in the passenger side of fron diferental it quit for a day and is mow back