Bad Bearings?

How can I tell if I have bad bearings? I can hear a rhythmic noise when I'm driving, generally at speeds over 45mph. It seems to be coming from the rear. The tires are almost new but it was doing it before the tires.

Any suggestions? I'm not seeing any unusual wear to any of the tires either but the noise seems to be getting louder.

How many miles on it? Wheel bearings usually don't go bad for a long, long time and I think they should be re-packed at 100K miles. Jack up one wheel at a time or get it on a lift and spin the tires and see if you can hear a bearing grating. If it's a bad bearing it would run hot and if you could feel the bearing housing it would of course be warm/hot. I guess it's possible for one bearing, (maybe defective?), to go bad and once it starts to go they go quick, hence, the noise gets worse quick.

How many miles on it? Wheel bearings usually don't go bad for a long, long time and I think they should be re-packed at 100K miles. Jack up one wheel at a time or get it on a lift and spin the tires and see if you can hear a bearing grating. If it's a bad bearing it would run hot and if you could feel the bearing housing it would of course be warm/hot. I guess it's possible for one bearing, (maybe defective?), to go bad and once it starts to go they go quick, hence, the noise gets worse quick.

I'm right around 91K. As soon as all the snow clears I'll jack it up and try that.