I just bought a 1992 W250 and want to go through the whole thing and replace the fluids, so I'm wondering how much I need for the front and rear axles and what weight I need for the transfer case? I was going to run 75 90 in the front axle and 75 140 in the rear axle, like I did my 04. It's going to be Royal Purpled through and through... :-laf