Tires are fine, proper inflated, rotated, balanced. If it were the tires, the car would not stop vibrating when I let go off the gas. This was verified by the dealers "ASE" certified mechanics. I called and the service guy is telling me that the manager is in a meeting and to call back. The transmission's guy says that its the transmission. Supposedly this guy also checks propeller shafts and its "supposed" to be fine. I asked the service guy about the one piece and two piece drive shafts and what would happen if the joint of the two piece wears off, he answered, "you would get a vibration". I mean, if I am right from reading all these forums and it is the drive shaft, why am I doing their f'ing homework.

 

Hello all, sorry for the long wait.Took the matter into my own hands and broke down the tires at my friend's dad's shop. The worst tire (right-rear) is in fact out of round. I think I'm gonna ride it our until the Mud-Terrains wear out (shouldn't take too long). Anyways, thanks for all the input.

 

When I bought my truck it had 4,000 miles on it and itcame with 35" Pro Comp Exterrain tires that were installed by the dealership before it was sold new. I noticed that it had a slight vibration at around 65 or 70 mph, but just assumed it was because of the oversized tires being out of round. I took it to a local tire shop and paid $170 to have them trued and balanced. Got back out on the highway the following morning and had the same issue at the same speed. I took it back to the tire shop and had them rebalance the tires.Got back out on the highway......same thing...same speed. Now I'm wondering if it might be the truck.