knock

The video in this post is from a 2019 JLU MOAB. It's lifted, 3.5in, running 37s. The dealership can't figure it out. I've checked everything i know to check. The knocking sound is present when you are between 8 to 21 mph and only when you let of the gas, slowing down. As soon as you accelerate...

Anyone with working LSD can check if rear tires will spin in the same or opposite direction when jacked up? Mine comes with LSD but appears to be spinning in the opposite direction. (Suggesting open diff or due to lack of load?)