I have a bad vibration, especially at 50 mph. It started as a litle vibration and now it's pretty bad over time. So far I've replaced...........

1. ALL bushings, front and rear with energy suspension
2. Rear axles, bearings and seals
3. Rotors, bearings and seals
4. Had driveshaft balanced and new U-joints
5. New wheels and tires
6. New shocks and struts
7. All front steering components. Centerlink, pitman arm, tie rod, etc.

I was wondering if it might be a bushing or bearing that the shaft coming out of the rear of the transmission might be bad. I pulled my driveshaft out of my 88 I-ROC and wiggled the shaft and noticed that it's not as loose as the one in my 91 with the vibrations. Has anyone had an issue like this before? When I drive down the road, the vibrations make my passenger seat shake back and fourth.