Originally Posted by nytevizion

Running a 2004 AWD Sedan 130k and noticed the hum about 5000 miles ago. No noise when cornering, or taking an expressway on/off ramp but it’s been progressively getting louder. As the noise got more pronounced I realized that it is definitely the front end, but is still very difficult to determine the side. I figured a bad bearing must be producing heat resulting from the excess friction. I drive about 60 miles to and from work a day. When I got home on two separate occasions, I laid on my back next to the wheels , reached in and checked the all four axles as close to the spindle as possible. If your fingers are skinny enough you can get even closer to the center of the shaft where it meets the spindle but mostly I just wrapped my hand around toothed area. I assume that is the end of the CV joint. It’s around 30-40 degrees outside and three of the points were cold. (Probably at air temperature) The passenger front was warm to the touch. I would say a 25 to 35 degree difference in temperature. I feel pretty confident that it’s the passenger front bearing that is going bad. This will be a DIY for me in the next week or so. I just bought the car, less than a year ago so this is the first bearing change for me.

I would suggest using caution with this method as I don’t know how hot this area could get with a really bad bearing.

Hope this helps someone.