Front end Whirring over 40 mph

I have a 2003 Trailblazer with 65K. I don't typically drive this vehicle (wifes). When I took it out the other day I noticed a whirring noise over 40mph coming from the front end. Looking closer I noticed the inside of both front tires were cupping. I had an alignment and rotated the tires... Still getting the same noise. I don't believe I'm just hearing the tires out back. Are front bearings an issue on these??? possible transfer case problem??? It sounds similar but louder to having the 4 wheel drive on dry pavement. I did verify that the 4x4 is engaging and disengaging.... It seams to be a speed issue not a load or rpm issue. If I go to neutral I still get noise.... I'm think its front bearings.... If so how hard are they to do on this rig??? Last time I did front bearings was a long time ago on a F-100 if that tells you somthing :wink: I guess what I'm asking are there any special tools needed such as a press etc???

Welcome to AF, sounds like a wheel bearing, see if there is any play in the hubs, when jacked up, a loose one always indicates it is bad. The actual replacement is not too hard, I cannot really advice you on the how to as your skill level and tool access is unkown. The how to should be listed at autozone.com, repair guides.

I just ran outside (38 deg. windy and raining... got to love New England weather) and did a couple of checks to see if it's the bearings.... Noise seams to be more a little more pronounced when turning to the right than left. This coupled with my previous info makes me believe it's the left front bearing... Jacked up the front and can't seam to get any play out of either wheel and both seam to spin about the way I would expect any wheel at that temp and disk brakes involved.... would you still be confident in the wheel bearing being the issue??? The bearing assembly on this truck is rather expensive.... so I hate to buy one for not. Any thoughts are certainly welcome :2cents:

Once you get it off you can tell if it is bad, sounds like the l/s. If you are wrong put it back and go to the r/s.

Thanks for the sanity check! Any thoughts on where to get a quality bearing assembly at half price:biggrin:

Not really, I use Napa parts, they are less than OE, just get the premium one if there is a choice.