I have an 04' Quad Cab 4x4 Hemi with 122,000 miles on it. Runs great, but at highway speeds and at other points, I get vibration in the rear of the truck. I have two brand new tires on the back (200 miles on them) and the fronts have about 2,000 miles on them.

When cruising down the highway the trucks feels like they aren't balanced in the rear. But they were just mounted and balanced. The old ones felt similar and when I removed them, they were visibly scalloped.

Has anyone experienced this? Any ideas? Is it shocks? At my mileage should I look for something else?

THanks