correct trans fluid for 88 2wd auto

i have been told to use atf4 not dexronIII since the latter is not recommened for later xj's but mine is an 88 which seems to be in a grey area as to the articles i read on dexronIII. i have an aw4 trans not sure what fluid type is in the xj now but it appears clean and filled. any input on this(no owners manual)will be helpful...dealer parts at one dealer said they use atf4 on all auto xjs regardless of year another said there is no specified fluid on their puter for my jeep but dexron III would 'do'.....i am waiting on a haynes manual to arrive but in the meantime....

as to diff fluid is 10-90w ok?
tia

Anything DEXTRON II and up will work. I use DEX III.

I pretty sure 10-90 doesnt exist. If you meant 75-90, then that will work fine.

thanks
seems that up to 93 dexIII is the fluid. but later xjs need atf3 or 4. http://www.allpar.com/fix/trans.html

on the diff what is it you use? 90w what brand? i plan to take the cover off reseal it then refill but in the meantime want to fill it to the plug hole and run it for a few days.

Any brand of gear oil will do. Just make sure its rated GL-5 or says its good for hypoid gears