I did one of my fronts bearings but it was a much different noise. And I was able to diagnose it without having a rack - as when I moved the rack side to side to put more lateral pressure, the noise increased.

I eyeballed the beejezus out of the wheels - does not look like a weight has fallen off.

Tires asides, can't seem to reason why I don't hear the noise in the drivers rear even though both tires seem to have the centers with the slightly more wear ..... I hardly drive this car but plan to take it for a week to go through it's motions.