What do you mean it has 16 inch?
Not sure, but I would consider the pinion angles (or the angle of the Driveshaft in question).
Also it could be an unbalanced driveshaft.
I would maybe take it in to a shop that makes/specializes in DS and have them take a look at it.
Any Jeepers in Edmonton, AB
I am on channel 33.
I live, I ride, I am JEEP.