I recently drove a '95 GT 5 speed coupe that has a NASTY vibration. The vibration is very pronounced under acceleration. Its there while not under throttle, but as soon as you give it some gas its vibrates much more violantly. I got under the car and with the car on jack stands and the ebrake on, I couldn't feel any slop in the U joint which was my first thought. I wanted to see if anyone else had any ideas. I did notice that the harmonic balancer needed replaced too since it was wobbling quite badly. The car has 130K miles and is 100% stock except for underdrive pulleys and a short throw shifter. The clutch feels likes its on its last leg as it engages clean at the very top and there is no adjustment left in the stock quadrant. Does anyone have any ideas as to could be the cause?