Roaring noise

I have a 2002 GMC Senoma 4WD. I have recently noticed a roaring noise in the area of the left front wheel, The noise is assocaited with rotation of the whell. There is no unusal tire wear or shimmy. I rarely use the 4WD however when I engage the 4LO option the noise gets louder. Any ideas?

A worn wheel bearing is the first thing to check.

Tester

When the front wheel bearings started going on my 2000 S10 Blazer it sounded like tire noise. Does the sound change pitch or volume when the steering is turned off-center (i.e. changing lanes). That is an indication of a bad or failing bearing.

Ed

Wheel bearings frequently wear out and get noisy on these trucks. They are easy to check. Any decent mechanic can diagnose it in minutes. If you have the willingness and the tools, you can check it out yourself. Raise and support (with jack stands) the front end with the wheels off the ground. Make sure the truck in in 2WD. Give each front wheel a good, strong spin. You will hear that rough, droning sound of galled bearings at whichever wheel bearing is bad. They are easy to replace on this truck, but don’t cheap out on the parts. You get what you pay for with wheel bearings. I have had the best luck with Timken and National.