2001 duramax 2500HD 4x4 auto
Can someone tell me what other oil there is out there, besides Auto-Trak II, that I can use in my case? I can't seem to get any oil for it from my local parts stores. Nor do they have repair manuals such as Chilton for my truck. I feel like I have a concept truck or something. I can't even find how much oil the transfer case holds.