Hello, Yesterday I changed my '03 Yukon's AWD front differential fluid. The magnetic plug made me a bit nervous. I bought the truck with 150,000 and no service history. It now has 160,000... I would say it is possible it has never been changed, but who knows. Anyhow, on to the plug. I took before/after pictures as well as a photo of what was stuck to it smeared out... There were no big pieces or anything, and it almost looked like anti-seize compound when I smeared it on paper. Should I be concerned? It seems to be driving fine.