Did the new hangers fix the issue? It sounds as if I have a similar issue as yours on my 2011 JKU.

 

I tried the cheap pipe hangers they sell at the auto parts stores and it worked for a while, but it wasn't strong enough to hold up the exhaust. I'm taking it to a muffler shop to get them to weld it up to keep it from dropping. I did take the diff covers off to be sure it wasn't my gears and they looked good so the exhaust is definitely where the rattle is originating.