Think my origanal thread was lost in the server crash so here is an update...
I took the car to the Ford dealership and they said that there was no driveline vibration. There IS a vibration at high speeds...80+mph so I bought an FRPP Aluminum driveshaft and installed it. The car is silky smooth at low speeds with very little vibration. But the high speed vibration is still there. It is coming from the rear of the car. I almost wonder if it could be the tires? I had 315 DR on there and it only vibrated at 117mph. Now with these 285 Goodyears I seem to have a vibration from 80+. Or maybe the 4:10 gears need to be reset???
I took the car to the Ford dealership and they said that there was no driveline vibration. There IS a vibration at high speeds...80+mph so I bought an FRPP Aluminum driveshaft and installed it. The car is silky smooth at low speeds with very little vibration. But the high speed vibration is still there. It is coming from the rear of the car. I almost wonder if it could be the tires? I had 315 DR on there and it only vibrated at 117mph. Now with these 285 Goodyears I seem to have a vibration from 80+. Or maybe the 4:10 gears need to be reset???