Hey brothers!!! My "other ride" is a 83 1/2 ton(6.2, 700r4, 3.42s). About 4 years ago, I replaced my driveshaft support bearing and my rear u-joint. Ever since then, I've had a relatively subtle vibration that comes on at about 40 MPH and disappears at 60 MPH. The vibe also happens if I pop the tranny into neutral at those speeds so it has to be driveline related. I've checked and rechecked absolutely every possible cause of the vibration. I've even replaced my tires. All the u-joints look good and have been greased on a regular basis. I doesn't look like the driveshaft has dropped any balancing weights, either. I'm starting to think that I'll never solve this problem. Could someone start throwing ideas at me? Thanks, brothers.