Anybody???
Beuller??
Yeah, that's a LOT close.
What's loose? Ball joints, or is the axle loose in the hub bearing?
Anybody???
I had the exact same problem @ 76,000 miles. Always around 60 - 62 MPH (about the RPM that you identified). Changed the U-joints, aligned the tires, balanced the tires, rotated the tires, new ball joints, wash and waxed the truck (just kidding about that one) and the sound still persisted. Drove round trip Mass. to Mich. then had to replace the u-joints again. We then looked at the drive shaft and found the problem. There are small welded-on weights (they look like drops of steel) for balancing the drive shaft. Two were missing. I had the shaft rebalanced (about $125.00) and no problems ever since. When you inspect the shaft it is pretty evident where they were welded and then broken off. Mine were missing on the rear of the shaft - mechanic said this sometimes happens when driving through snow banks or mud holes.