I have a question for you guys, I have a 2001 Chevy blazer with 156 thousand miles and recently i've been hearing this humming noise inside the cabin.

It sound deep and mellow and starts around 45 mph, its a noise that i've never heard before, it kind of sounds like the tires are underinflated.

Anyone have any ideas what it might be? Differential? Differential Fluid?(dont even know if it's ever been changed) <<I'm leaning towards this

Oh and the truck was flipped in 2004 at around 80 thousand miles, but i doubt that has anything to do with it since it was so long ago and the noise barely started. Other than that the engine and tranny run really good.

 

It most likely is a front wheel bearing going bad. You may be able to hear a difference when turning either right or left. If the noise gets louder when turning left, the right front is the source. If the noise gets louder when turning right, the left front is the source.

I just went through this on my Rainier. I could not tell a difference in the noise turning either direction, but I could definitely hear it more on the driver side. Removed the driver side hub and sure enough it was the source of the problem. No wobble or even rough running when turned slow, but turn it quickly and it would speak up a bit.

 

U joints brother. If it's 4 or AWD possibly spider gear assembly or front drive shaft. I'd bet U joints.

 

You might have a bad front hub assembly. I have the same symptoms. The way I checked this was lift the front end, and spin the wheel. It sounded like it was form my left front, so then I pulled the tire off, and the caliper, and spun the hub, and it made the same noise. So just lift it up, and spin the tires.

 

Its a 2wd.

 

I'm pretty sure i dont hear a difference in turning, and driver/passenger sound just about the same.

but I guess the wheel bearing is my next fix, which kinda sucks because i'm in high school and broke lol

I will jack it up tomorrow morning to see how it is, i'll let you guys know! Thanks!

 

The plus side with a 2wd is once you get the brakes off, you have open access to the hub to feel/listen to how it spins.

 

well that makes me feel a little better lol

Would a bad alignment cause this?

 

Nope, but the flipping of it in the past certainly could have. the good thing is you can get new berrings/races/seals and the tool to remove/install them in the rotor for less than a hundred bucks. Change the races too, not just the old berrings. You are lucky you dont have a 4x4 they cost alot more.

 

I believe the newer blazers actually have the whole hub assembly as one piece. You can't just replace the bearings.