I use 15w40 Diesel oil in my AX15, works great.

 

You can use 10W-30. 2 weeks ago I just rebuilt mine as the synchro's went.. I have a 1988 Dakota and I actually think I may have grenaded my NP A535 transmission by using 80W-90 shortly after putting it in not knowing better. The transmission shop that did the rebuild for me actually suggested using ATF Fluid. They also recommended that it was slightly overfilled.

Reason I put 80W-90 in was that I have a 1966 Chevelle with a 3 speed manual which calls for that and I actually assumed most manual transmissions used gear oil which I think was a huge mistake.

I wish I knew why I was told to use ATF instead of 10W-30. I was looking at temperature viscosity comparision, it appears ATF fluid has a more consistent viscosity at a high temperature range, from cold to hot as opposed to 10W-30 oil.

 

Yours being a 95, and assuming you do not have the owners manual, I would look in the FAQ at the top and download the service manual, then follow its advise on fluid. I can tell you, my 87 NV2500 called for 10w30 motor oil, I have a NV3500 now, and it calls for syncromesh fluid, Yet I have a friend with a 95 jeep and a NV3550 trans and it calls for 80w90 gear oil. So again, download the manual, "its freee" and follow its instructions.
Of course, if you do have the owners manual, just look in there.