I own a 2002 TJ and had it lifted to 4' with a transfer case drop when I first purchased it, I now have 36,000 miles and started having a vibration recently. It is only on acceleration or deacceleration, if I put it in neautral or press in the clutch, it goes away. I had a mechanic look at it who said I had play in the differential and that it probably needs to be adjusted to get rid of the vibration. Is this possible or should I look into getting a cardan shaft? I had no problems prior to this.