The engine and tranny are one piece. HD now makes one oil that can be used in the engine, tranny and primary, saves a lot of hassle. And yes Kyle is gay.
It depends on what year the bike is. The earlier Sportsters had an oil transfer valve between the engine and the primary. The engine, primary, and clutch all shared the same oil. I think they got rid of the oil transfer valve around 1977 or 78. If the bike is newer than that, yes; you use different fluids for the engine, clutch/transmission.