I have a 79 F150 400M C6 Trans 4x4. What kind of fluid goes in transfer case? I thought 80-90 but a repair man told me Dextron II trans fluid. Help!

 

If your transfer case has an iron housing it takes 80-90. In 1980 Ford went to an aluminum housing transfer case. All aluminum transfer cases use atf.

 

The Np 205 transfer case i have. It calls for 50 weight motor oil and 30 weight if hard shifting is expierenced in the winter. My case came from a 78 F250 4x4 with 400m and c6 trans. Thats what the owners manual stated. If you look in the haynes repair manual they say 140 w gear oil. If you look in chiltons they say
Dana 21- 50w motor oil
np203: below 32f, 30w motor oil, above 32f, 50 w motor oil
np205: 76-77 50 w motor oil, 78 and later sae 90w gear oil
np208: Dexron 2 atf
borg warner 1345: dexron 2 atf