Hi Malcolm. The EP refers to the Extreme Pressure additives in gear oil that needs to withstand sheer so my natural inclination is to use EP oil in transmissions other than in an LSD axle.mI could never bring myself to use the factory recommended ATF which is an thin as Red Barrel. I was recommended to use Castrol SMX (or whatever it is now) synthetic oil. The gearbox oil pump is a tad limited in capabaility and apparently heavier oil can challenge the pump and render it u/s; improved apparently on the R380 gearbox.
