I twisted the splines on the trans yoke a few weeks ago and that made it vibrate real bad at any speed so I got a strange yoke and had a driveshaft made. I got the new driveshaft in yesterday and took it for a spin. It's smooth as butter til you hit 75 mph then something starts vibrating so bad it'll shake yer teeth out. If I put a little pressure on the clutch pedal I can feel it vibrate too. It's not rpm dependent just mph. The driveshaft was balanced, at what speed I don't know but it was balanced without the new yoke. Any ideas? I'm really sick of this car! :angry: