Nope, not my skid plates. Thx for thinking though...
I went ahead with your advice and got only transfer case skid plate. It's still sitting in my trunk though, since someone didn't know what to do with it LOL
Just kidding. Good thing it wasn't on. At least dealer had easy access to the transfer case. It's mechanically sound.
Now I am leaning towards the idea it's something engine-tranny related. It's just the pattern the noise comes on... always related to speed and rpms... still working on it...