transfer case won't go into 4lo.

hey guys, i just got a rusty, crusty, POS 91 xj for the cheeeep.
It is quite possibly the best running and quietest xj i've ever owned. It has the 4.0, AX15, and NP231, and a CAD front axle. It's obvious that the axle actuator isn't working, and i know exactly what to do to pin it to always be engaged, or even swap in a solid long side shaft, so that part isn't a concern.
i've also had a couple of np231's split open and put back together succesfully, and have swapped every single mechanical part that can be swapped on an xj at one time or another.
but i've never had a rusty one, lol.
if the shifter simply stops at 4hi like that is as far as it goes, what do ya do? the jeep drives great, shifts great, and is overall a decent DD, and will be one that i cut out and replace all the rusty parts on eventually, but for now i want to work out the few mechanical issues before i start building it to wheel.
i'm hoping that the issue is simply a linkage adjustment deal, and not something that will require a transfer case rebuild or replacement, because that will add significantly to the overall price of my cheap beater.
thanks for the help, folks! wanna get this mother out in the woods ASAP.

You could try to disconnect the linkage at the transfer case, then see if the T-case itself will shift into 4 low. The linkage arm on the T-case should be able to be shifted with a wrench on the mounting stud.

That way, you'll know if the issue is with the case or the linkage, and proceed from there.

David Bricker / SYR

that was gonna be the next move. i'm just fishing for ideas right now, since i can't really do anything to it for the next few days.

problem is definitely in the case. the linkage moves fine, and i pinned the CAD to see if 4hi does anything. it clicks in fine, but still doesn't work. my buddy is gonna trade me a case so i'll be able to wheel, and i think he wants to take my case apart to see what's wrong, and install a short shaft sye in it. at least we don't plan to swap it and throw it away when there probably isn't much wrong with it. not even a wierd noise, just no 4wd.

most likely the shifter fork and sliders on it are toast.