The early spec said auto fluid but it later was updated by factory as auto was found to be a problem.
I use Transgear penrite full syn 70 - 75. This only not the 75 - 85,90.
I talked to penrite direct and that is what is what the adviser told me he used in his own Jeep. It is thin like what the factory suggest. Also agri hyd fluid usually 5-30. but both feel thin as required.
Penrite seems to be a little out compared to other lubrication guides. Coolant for my wj, my wh and patriot all green, but nulon now is red for 3 and or their long life universal.
Well I will run some with green and some red as I need red for the com. I tonner.
But the Jags all use green so all the green will not go to waste.
Mobil 424 is not full syn oil.
Just my 2 cents worth but i spent hours chasing this and for power steering for all of these. The power steering is worst. I will use some of my jeep stuff in my Jags as it is better specked.
Good luck but I would do a little more research before auto fluid in the transfer case for the V8.
Good luck
Peter