Hello, I have a 4x4 2007 Silverado 1500 Classic with 3.42 gears, 140K miles. I am getting a howling noise that is loudest at 40-50 MPH. I believe it is coming from the front driver side but could just be the front center of the truck. The sound is actually loudest when coasting down approaching a stop light or driving constantly at about 50 MPH. The sound does change with speed. If driving constantly at 50 MPH the sound gets loud for 2-3 seconds then goes almost away then comes back every 2-3 seconds. It is not a wop wop wop noise of a tire or a rar rar rar noise of a wheel bearing it is a longer slower howl type noise.
The truck has cooper ATP tires that I have rotated several times to see if the sound moves. It does not seem to be tires as rotating tires makes no difference. Both front wheel bearings are new within the last 2 years. I had both of them start making the typical wheel bearing noise that changed pitch when turning. The noise I have now sounds very similar to a wheel bearing but does not change at all when turning left and right.
I tried running the truck in 4wd the other day. The noise stayed the same in both 2 and 4wd.
Any other tips? Or things to check?
Ryan