I have an 06 ram slt quad cab with hemi. Around 60mph it shakes. I believe theres a problem with the cylinders cutting out to save gas. The dealer cant figure it out, the changed the drive shaft-didnt help. They then said the vibration is normal, I dont buy it. It only vibrates at 60mph, not before and not after I accelerate past 60 but sometimes when I let off the gas. Can anyone please help???

 

could be something in your front end like a tie rod or rack. how many miles on that truck? maybe check the tires.