99 Dakota 5.2 4x4 auto 78k miles. All stock

I've been chasing a scraping noise of sorts on my truck. The best way to describe it is when you have no brake pads left and you hit the brakes. I originally thought it was coming from the rear end. I changed the fluid and inspected everything. The diff looks fine. I jacked the truck up with the rear tires off the ground and had my father in law attempt to locate the noise. He said the noise was definitely coming from where the drive line attaches to the trans. I crawled under it and the drive line has no play at either end.

The noise starts around 10 mph-15 mph. It's not real loud and doesn't get louder with acceleration or increased speed. However, when I let off the gas the noise will go away for a sec or two and comes back while coasting. It does make a loud clunk noise shifting into drive or reverse but from what I read that's pretty normal for dodge. I would really appreciate any help. Thank you

 

check your universel joints

 

Also check to see if there's oil in your transfer case. Sorry if that seems obvious, but simple things often get overlooked.