very interesting and my front and rear diff along with my transfer and trans ( manual) have had the fluids changed twice in 103k miles it now has on it. the origanal went to 50k then again at 90k just because it recieved a new clutch lol but yes people do forget how much heat diff and trans and tranfer cases really do see! interesting info on the oil though! i used the motocraft brand and don't see that listed so i wonder who makes that for ford? i will have to look at the rating on the bottle now.