Bearing Noise
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, 2003 Chevrolet TrailBlazer, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.
Faulty bearings produce a rough growl or grating sound, rather than the whine typical of gear noise. Bearing noise (hum) will pulsate at a constant vehicle speed. This indicates a bad pinion or a bad front axle side bearing. This noise can be confused with front wheel bearing noise. Inspect and replace the bearings and the affected components as required.