What kind of oil is everyone using in there transfer case? I have a 2000 S-10 Blazer with the 4 button auto trak. I believe its the NP236?? The only oil the haynes book calls for is GM Auto Trak II fluid.

 

That (GM Autotrak 2) is the ONLY fluid that is recommended to be used. Considering that it uses a little under 2 quarts, just spend the money and get it. There are some companies that have made attempts at marketing something that they say is "compatible", however, they will not be the ones replacing your transfer case if it fries the clutch pack.