Well, as it turns out I did something stupid (big surprise). There wasn't a thing wrong with that bearing, that I replaced last Saturday in my driveway. I'm going to put new rear brakes on it, even though there is some life left to the old ones. I now feel pretty sure that the sound is the rear brake dust cover and I just missed it. I was so sure it was that axle bearing that I didn't seriously look at the dust cover, which would take like ten minutes. The dead giveaway is the fact that in a left turn the sound goes away. Well, changing out the bearing was a fun Saturday so, it wasn't a total loss. Now I know exactly what's in the drive shaft, differential, axle, rear brakes, wheels, etc..