I've done a lot of searching online and I can't seem to find any specific answers to this regarding the AWD Suburbans. I just purchased my 2004 Suburban with the 5.3L and its AWD. It has 111,000 miles and we are getting ready to take a long road trip in March and i want to get the 100K services finished before I take it out. What fluid should I use in the transfer case? There seems to be a lot of discrepancy between going with what the manual says and what should actually be used. Anyone else out there have the AWD and know exactly what I should put in there? Also, some info on differential fluids would save me some research too!

Thanks! If there is a specific post about this, I couldn't find it and would appreciate a link!

Jim

 

Well, you can first take a look at the Identificator tag at the rear of the transfer case where you can see on the first line of it three numbers that represents the following:
1st digit: 1 - single speed; 2 - Two speed
2nd digit: 2 - T Utility; 3 - Truck, L - van; 4 or 6 - K truck and utility
3rd digit: 1 - manual, 3 - electrical shift; 6 - automatic; 9 - AWD
Automatic NP8 transfer case uses the Auto Trak II oil (blue color)
Automatic NP3, NR3 and NR4 uses the Dexron III oil (red color)
I hope this help you

 

I will use that information to continue my research. Thank you!