Hi everyone. Just wanted to share my experience with my 2016 F150 8 foot box super cab with a bad vibration at highway speeds which was much worse when you let off the gas or on deceleration. First thing was new tires. No difference. I did notice the vibration seemed to be a higher frequency then a tire balance problem and the rear view mirror vibrated really bad especially when you let off the gas and not as bad when you were accelerating but still bad. I am happy to say after buying a new complete 2 piece drive shaft from ford for $700.00 plus tax which in my opinion is not a bad price (shopped around on fordparts.com dealer websites) the truck runs like new. No vibration. I did notice before I replaced the drive shaft when I took all the load off of the drive shaft (blocked the wheels and in neutral the slip part of the rear section had play between the 2 sections. I tried removing the plastic bellow and putting grease but it did not help. Hope this helps someone solve their issue. I am a licensed mechanic and worked at a ford dealership in my past. I will never buy a Ram or recycled American motors as I like to call them as they are like buying a truck from the dollar store. Love my F150 as it replaces my 2005 F150 8 foot box super cab which with well over 300 000km and still runs well and yes it has the 5.4L engine which I had to do timing chain, phasers and spark plugs at 200 000km and is no where near as rusted out as newer Rams and GM's. It was worked hard while I had it. Ford has always been well ahead of their competition as dodge and gm still are using ancient technology over head valve push rod engines that expired 20 years ago. Yes I am Canadian sorry just my 2 cents. Next I need to get running boards. Someone removed them before I bought this truck.