What oil is everyone using in their vehicle? Engine: Shell HX-7 Transmission: Toyota WS*Cannot remember exact oil. Transfer Case, Front and Rear Differentials: Valvoline High Performance 80w-90 LSD oil for all hypoid diffs. My vehicle most likely came with Castrol in the diffs and transfer case from the factory and the Valvoline works just as well, there is no additional noises or problems with it. Very happy. The oil works excellent in the rear LSD and open front diff.