I have a 2014 4.3 2 wheel drive Silverado and I have a noise coming from somewhere on the truck. I can’t figure out if it’s the engine, the transmission or the rear end. It only happens under light acceleration between 30-60 mph. I loose power when it happens too. I took it to the dealer and ofcourse they couldn’t replicate the sound. But it sounds like Chewbacca. Anybody know what this is?