Just around 92,000 MILES. I was holding the two shafts and twisting them to show play in the U joint and there was obviously none. Judging by the shavings in the oil it is safe to say that the differential is at fault.
My model is a diesel and the diff is the same as in the 4.6is (i think). Will take 2-3 weeks to ship to my skybox and another week till I receive it in Trinidad. It's time to wait and purchase/fab up tools to remove the diff mounts and rear axle now. I cannot express my disgust at this diff.