With about 75,000+ hard driven miles and many spent in part time as well as full time 4x4, the front hub bearings are shot. I heard this annoying noise that I attributed to a more aggressive set of tires that were recently put on. Anyway, long story short is thank god I have the extended warranty.
So if you're driving around and you think that hum is nothing to be worried about, be sure to give the front hub bearing a once over.
