My original was an aluminum with 3.15 gears. Since I was going to have to spend my own money I decided I would upgrade to 3.55. I will be dissecting the original rear end in a couple of weeks to see what I can find.
After going round and round with Ford a bbb for over a year. I got a vibration analyzer and diagnosed it myself. It indicated the rear end was the cause. So I replaced it with a ford racing iron 3.55 rear end. Problem solved!! No thanks to ford.
Vehicle vibrations are caused by unbalanced parts rotating, road noise is random. I purchased this app and have used it on several vehicles and it is quite accurate. Not trying to sell it to anyone just a suggestion.
New member, I purchased my 2016 ecoboost mustang on September 3 2016 and it started vibrating in January. I have taken it to the dealership many times. They road force balanced the tires twice then replaced them and road force balanced again. Replaced the driveshaft and did not balance the new...