No it is in 2wd. And usually around 2500 rpms. It will do it at different speeds also. I brought it to the dealership and they are thinking it may be the serpintine belt slipping but it almost sounds like it is comming from underneath the truck. I’m hoping that it is as simple as a slipping belt!
I recently purchased a 2014 silverado 5.3 z71 4x4. I’ve noticed when accelerating hard I hear a whirl noise. It is most comming when accelerating hard around 35 mph. I am attaching a video of this noise.
DA398929-2ADD-4097-BC4E-233E2104CC47.mov