I have a 95 GT Conv. Im getting some vibration at speed, 85-100 mph. I just had the rear end completely rebuilt and new U-joints. The car has high mileage. Any body know what it could be? Im thinking a throw-out bearing or tranny prob.s but I dont know. Its un-noticeable at any speed below 80
I've heard of people getting a vibration if the driveshaft isn't balanced properly. Perhaps your driveshaft is just barely out of balance? Also, did you upgrade your gears recently? You can get a harmonic vibration in the driveshaft at higher speeds if you upgrade your rear end gears.