I recently put a 4" suspension lift on my 05' TJ wrangler. Love it. Although, there is vibration when I accelerate. I've already checked the pinion angles, got new tires, and got alignment. I am starting to think that the back track bar is too short? Any idea how to check and see if it too short? The extension prices the lift came with didn't work therefore I just kept the old track bar. I bought the jeep with a 2" lift already on it so I am unsure if the track bar I have on there right now is stock? Help!