I have a 2008 Dodge Ram 2500, 4WD, 6.0L diesel. I bought it used with 30,000 miles. I am noticing a vibration in the steering wheel and in the seat that feels like a chugging between 40-50 mph. After 50 mph, the truck no longer chugs, but it does vibrate. It is felt whether coasting or accelerating through 40-50 mph. Other sites have said that the vibration is caused by the front wheel ball joint, or front/rear wheel bearings. Please let me know what you think. Thank you.