Hello, I am having a time troubleshooting this one. 1999 Grand Prix GT non super-charged. If I accelerate slowly or moderately, my car does fine. It is only when I accelerate more heavily that I get a vibration in the front end. I can see and feel the hood, fenders, etc vibrate. Not brake related, as I am not on the brakes. If I get on it while I am moving, it does not vibrate.Is this a sign of a new tranny needed? The half-shafts are fine, or at least installed fully.