Thing is on my issue is it is louder at times than others, no matter the speed... Top it off it kinda comes and goes! I am lost here, I have been told it could be like 8 different things from friends and family...

 

To ZKILLER396: Your noise between 40-65 mph sounds like a bad wheel hub. /The others sound like 4WD issues/. Some on forum say you should be able to swerve left and right on a deserted hwy and the noise should lessen on one side. That means when the bad bearing is 'unloaded', the noise lessens. Mine wouldn't do that. It did get louder and louder and at lower speeds. If you can put it on a lift and raise all four tires so you can run it safely. Run til the speedometer indicates 40 >. You should then be able to hear which bearing is making the noise. This test can also eliminate the possibility of a separated belt in a tire which can be a similar sound. If you still want to check for the separated tire, swap both front tires to the back. The noise should move to the back if it is a separated tire as someone has already suggested.
The others posting noises sound like 4WD problems.

 

This issue is very tricky and kind of difficult to figure out. I have a Blazer 2000 4x4 and I have the same whirring noise in the front end. It’s kind of an on and off noise and it seems to go away when 4x4 is engaged. My front suspension is rebuilt so it’s not the suspension. Transfer case oil is fine. Today I checked the front differential oil and it seemed it was missing some oil so I filled up and now it seems to have calmed down a bit. I really hope this could be the solution. I’m going to give it a few days to see if the noise settles down before I start tweaking on it again. If it continues I’m going to keep checking and keep trying to keep finding the solution and I will keep posting updates to let every one know what it can be because this is a very annoying and tricky issue to figure out

 

Did you fix this problem? With mine if I engage to 4Hi noise goes away. But problem still there when I put in 2hi. Anyone here was able to fix?

 

Hi did you figure out this problem? Mine just started 2005 Chev Blazer 3 button. I really dont know whats causing this.