I would be tempted to run my hand along the top of the case, and see what you feel, or try and get a look up there with a bright lite, and mirror. Drop the crossmember if you have to, to get more space to look. That is NOT a place I would expect to see that type of spray pattern.

 

Just to follow up, changed the transfer case and problem solved. Previous owner ran the transfer case without fluid which I realized when I drained it. Think the sling was from the prop shaft in the end. Case didn't have any breaks when I pulled it off.