My 2004.5 dodge cummins came with Dexron 2 in the transfer case. I'm not a big fan of light weight oils in gear boxes. I have been running gear oil in my transfer case in my 96 dodge cummins for over a 150000 miles with no ill effects. So I filled the 2004.5 transfer case with 75/140 #167 Schaeffer's. Im hoping the Schaeffer's will give me a quieter,better protected longer, lasting transfer case. whats your opinion ???? thanks,doug