Does my transmission share fluid with the transfercase or do I fill them separately

 

Welcome to the forum

They are separate

What they use is here: https://www.therangerstation.com/tec...ds-capacities/

 

Have you changed your fluids yet?
The transfer case drain and refill plugs take a 10mm Allen wrench. Crack the refill (higher one) first to make sure you can easily refill.
I did mine a while back and a notice had gone out that Ford back-specced all its transfer cases to Mercon LV. I used Valvoline Maxlife Dex/Merc LV with success.
The movement through the ranges (2-Hi / 4-Hi / 4-Low) became brighter and more definite.

The transmission pan drop (replacing filter and ~1/2 the fluid) didn't change anything I could sense but it feels good to maintain a major part so easily and inexpensively.