Stupid me, that is. I grabbed the wrong red bottle and put in about 100 ml of Motorcraft Synthetic 75W-85 before I caught my mistake. This was the first additional fluid after draining the trans so some contamination remains even after draining most of it. I started over with the correct XT-11-QDC and the trans seems happy. My question is: Should I change the fluid again soon in order to further dilute any remaining diff lube, or am I good to go.