Name that transmission

What was the four speed behind a four cylinder in a 1987 MJ 4x4? Is it worth having? I met a guy in town today who is going to sell his truck, and if I'm not going to have to worry about the tranny, I'd like to get it. It was in the Home Depot parking lot, so I wasn't going to crawl under and look at it, but I wouldn't have known what I was seeing anyway. Oh, and this was a ranch truck, so it is in rough shape. Thanks.

AX-4. Same as the AX-5 but w/o the fifth gear section (natch!). Decent tranny, plenty adequate for the 4-cylinder but not what you'd want behind a 5-liter Mustang conversion.

BTW -- are you sure it's a 4x4? I didn't think they sold any 4-speed 4x4s, even back then. I have an '88 4-cyl MJ with that tranny, but mine's a 2WD (for now).

I am more sure of it being a 4x4 than I am of it being a 4 speed. I didn't really get to look too closely, but I did see the t-case lever. I didn't really notice that there was no 5th, but the owner said 4 speed. Thanks.