It's possible other hands have been there I have no way to know. I did take the cover off before I put it back under the car and it was very clean and the ring was date coded correctly. I made the ASSUMPTION that it would be fine. I have thought about checking the pinion nut for proper tightness. As I've gotten older, I don't have the same arm strength as I had 20 years ago so it kind of intimidates me to try that, but I guess I don't have anything to lose.