It should tell you on the transmission dipstick.
transmission- 80-90w gear oil transfer case - atf tranny fluid
You can purchase mercon dextron atf . It will work in Ford and Chevy's.
5 quarts of Dexron automatic transmission fluid (ATF) according to my Hanes repair manual
You would add ATF through the dipstick tube.
Mopar ATF+3 or Mopar ATF+4
Pull the dipstick. Either it'll specify it right on the dipstick or it's just mercon3 basic atf.
Youre truck or blazer shold have new process 203 transfer case in which case you should youse youre manuals recommended gear oil most likely 90 wt
in the dip stick tube
The filler plug is on the right side of the transmission. Its easiest if u have a pump to do it . It takes gear lube not atf.
Dextron II--ATF
dextron II fluid.
mopar atf+3 or atf+4, do not use dextron