Found these looking for info on my drivetrain, pretty good info about major components for various vehicles.
They have a lot, these are two Jeep ones. I'm switching my transmission and transfer case to Royal Purple synthetic fluids, turns out 5w30 synthetic is a common upgrade for the NP231 and means I can carry one less variety of emergency fluid, my engine uses Mobil 1 so I'll just carry extra engine oil from now on. Also found out that TJ NP231s can pull the rear shaft without losing fluid.