According to the Jeep Service Manual:
"RECOMMENDED LUBRICANT
Recommended lubricant for AX 4/5 transmissions is Mopar 75W-90, API Grade GL-5 gear lubricant, or equivalent SAE rated gear lubricant. Correct lubricant fill level is to the bottom edge of the fill plug hole. The fill plug is at the passenger side of the adapter housing Fig. 4). The drain plug is at the bottom of the case. Approximate dry fill lubricant capacity is 3.3 liters (3.5 qts.)."
Again, though, I recommend Redline MT90, as I have had great results with it...