Hello this is my first time on this forum. I have a 2005 sport Trac adrenaline I’ve just had the motor rebuilt transmission rebuilt transfer case rebuilt front bearings replaced radiator differential resealed and I have A vibration that nobody can seem to figure out at the mechanic it is very obvious to me on the highway I can hear it and feel it underneath in the driveline somewhere. The best bit of information that I can give is that when I am on the highway if I put it in four wheel high the vibration completely goes awayAny help on this issue would be greatly appreciated as I’ve got $10,000 in this truck already and can’t afford to fix any more parts that are not the source of this vibration

 

Read a little information on ,"Driveshaft phasing", since this could be the source of the vibration.

Once you know what you are looking at , you will spot anything out of the ordinary. The hardest part is reading the instructions, the rest is easy because you will be able to spot the problem just by LOOKING.. If you see the problem, have the people that did the work go back and correct what they did.