If you are somewhat mechanically inclined this should be easy to figure out. Jack the front end of the vehicle up just until the front wheels are off the ground. With one hand at the top of the wheel and the other at the bottom, see if you have any play in the wheel. There should be no to very little movement as you push the top while at the same time pull at the bottom. Then move hands to the 9 and 3 o'clock positions and pull back and forth. It would be helpful if you have someone looking under the vehicle for this one. See if Your tie rod end is worn. Again, There should be none to little play. A bad tire will also cause the shake, even a rear tire. Look for a broken steel belt on the tread or a bubble on the inside of any of the tires. Country boy could also be right with bad bushings, You should be able to tell by pulling and pushing on the tire as I described above. My top things to check would be Bad tire, tie rod ends or bushings or even a warped rotor.
Have the *front lower control arm bushings checked or replaced at any Chevrolet or Buick Dealer. They have the special tools to press the old bushings out and install the new ones within 35 minutes.
I would start with looking to see if a belt has broken in the tire
It seems all right up to 30 m.p.h. then starts to shake in the front area ( I feel it through the steering column) and continues until
I get to highway speeds. The wheels seems to be where the
problem is so I suspect the brakes. After a few miles the shaking
dissipates or stops and it returns to normal. But I also notice that when I apply the brakes there's shaking also.
