I have an 02 Avalanche that has started making a humming/buzzing noise. The noise has been getting louder so i stopped driving it. I did notice it goes away when turning to the right but comes right back when you straighten out. Turning to the left doesn't matter i can still hear it. The best time you can hear it is when you let off the accelerator and let it roll (that's when its the loudest). I Looked under the truck but did not see anything out of the ordinary.

2002 Chevy Avalanche 1500
5.3L V8 4WD

 

It could be the universal joints, cuz they never get lube, no grease zerk.

 

I have the same type of issue mine hums when. I turn to the right like going down an exit ramp and no one seems to know what the hell causes it I figured a bad caliper ? Wheel bearing nope I've done both kinda sounds like it comes from the rear end right?

 

Hello, Maybe it could be the Hub assembly, where the bearing are at. But that would be the front wheels. I had the noise and steering wheel felt rough as if no hydraulic fluid. Changed out both hubs and no more noise.