2002 Suburban Loud wail

I have searched these forums and haven't found exactly the problem I am having. I'll try my best to describe it.

When just rolling along at 45 to 55 MPH, pushing the accelerator down just to maintain speed, there is a loud "WAAA" sound accompanied by vibration along the chassis. This is especially annoying because the speed limit around Tallahassee is generally 45MPH... so I mainly want to cruise at that speed. Primarily I drive a 1978 MG Midget -- I'm quite used to loud drives and vibrations, so I'm not just whining when I say this Suburban's wail is annoying.

If you accelerate through that zone to 65 MPH+ there is no noise other than normal engine acceleration.

People in the back say it sounds like it's coming from the rear. When I drive, I think its on the passenger side under the hood. Passenger things it's on the driver side under the hood.

The WAAA is similar to the sound of a vaccum cleaner and the fine vibration can be felt in the steering wheel, the accelerator pedal, in the dash. The vehicle has no functional problems, I took it to a few mechanics who didn't find anything wrong. I guess I have the 4.3L Vortec engine? I haven't done any modifications -- it's the 2WD version.

A possible source of this could have been from a prior accident that I don't know about (my grandfather bought it used at an auction) or the fact that it was used for hauling horse trailers along the state of Florida. ~150k miles.

Any ideas? Thx.

I have the exact same thing and was wondering if you ever got a resolution on this?

I didn't get it solved before a failure, so it's hard to tell you what exactly the problem was. My rear differential failed completely one day with a violent crunch. The car wasn't able to move anymore and grinded up the diff (of course). I got a used one to replace it and the wail is gone. Car runs great now.

Thread closed, way too old now.