Well i figured out where my part-throttle thump was coming from. I have some pictures of the differential removed. The picture quality isn't that great but i'll try to explain what were looking at.
Side 1

Side 2

Zoom-in on side 2 even though side 1 holds the pin but side 2 is brighter.



Not much left of the casting and to many more miles and it would of been a complete failure!

The unit is being rebuilt by a company named Dahmer Powertrain INC.