I notice a faint humming sound above 30 mph. It's not a grinding noise nor does it pulsate - just a steady hum. It almost sounds like the same noise level as the exhaust - as if you're waiting for the transmission to shift but then you realize it has. So I know it's a wheel bearing and I'm pretty sure it's the rear, but how can I tell for sure it's not the front?

Car has 99,000 miles on it now. Any clue as to how long I have before it really starts to act up? It would be nice if I could wait for nice weather to do repairs. Might it go another 3-4,000 miles this way?

 

If it's in the front, the noise will come and go depending on the side when the steering wheel is turned while driving. If it's just a faint hum, ya should be ok for a bit longer. To check, safely support the car up..... then grab the tire and push-pull in and out checking for any play.

 

No come and go. It's a faint noise that is noticeable at about 25 - 30 mph and it get a little louder at higher speeds. Almost a hum or groan. I am almost sure it's the rear wheel, driver side but I'll replace both since they're easy to do. Thanks!

 

There's a "DIY" on here somewhere for replacing the rear wheel bearing assembly. Relatively easy to do.
Do the side which ya think is worse and go from there. Make sure to check the rear brakes.....as a sticky
caliper can cause the bearings to go bad.

 

The rears are super easy.
Pull the rear wheels off & turn the hubs by hand. If they're bad enough you'll feel them dragging.
But, as mentioned, it's not tough, so if you're doing one may as well do both. When I did mine I found a deal where the price for 2 was barely more than 1 alone.