I agree with Philly, you need to isolate the problem. Is it directional? Is it mechanical? Have you gone through the parameters, you may have 1 or 2 out of whack. Is it a vibration in high speed, or does it only happen in a slower speed, have you replaced the velocity tach, I would do that first. you need to get a little more specific. Throwing parts at a problem is fine when you are out of ideas or good trouble shooting options. But you haven't begun to look at all the avenues before you replaced parts.
