NP242 just took a crap on my '89 xj...swap?'s

Ok, so like the title says, my NP242 just bit the dust. I can't find any at the local boneyards. My questions are: Will a NP231 bolt up to my transmission? If not, could I use the transmission/transfercase assembly off the doner vehicle, without problems? On my 242, at the top of the rear tail cone on the left, is an electrical connector, and the 231's i've seen have a vacuum connector, what is the difference? I did find one 242 on a '96 grand cherokee, but the tail cone looked different, and it had a three wire connector at the rear instead of a two wire. Would that one work? Any input is greatly appreciated.

Yes, if it has the same input shaft spline count. There are two types, 21-spline and 23-spline.

Sorry! Accidental double post.

Spline count is the big factor here. Rebuild your 242 it only takes an afternoon to do a complete rebuild unless you broke the cases.

242's suck. but hey that's just my opinion. find yourself one out of a 91 or older with a 231 and swap it out. shouldn't take more than 2 hours if you take your time.

scorpio_vette said:

242's suck. but hey that's just my opinion. find yourself one out of a 91 or older with a 231 and swap it out. shouldn't take more than 2 hours if you take your time.

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But am I going to run into any vacuum issues at the t-case if I use a 231? I don't see any vacuum lines on my 242...

You cant use a 96+ transfer case, the input shaft is longer on them so it won't fit. And Pre-96 will work though, as long as the spline count matches. But if you go to a 231 you will need the linkage as well. As for me I will take a 242, I love the full time 4wd option.

89xjgrey said:

But am I going to run into any vacuum issues at the t-case if I use a 231? I don't see any vacuum lines on my 242...

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Just seal the vacuum holes with like a screw or something, thats what I did and my 4wd works kosher.

Don't worry about the vacuum stuff, that connector unscrews from the transfercase, and you can just put the electrical one back in the new case. The threads are longer on the 242 though so you can only put it in halfway, just seal it up with some silicone.

The only other parts you're going to need are the shifter gate from the donor and the shifter bezel. Just make sure the 231's from a Renix Cherokee and you'll be fine. It's an easy swap, I did it to my 89 XJ when my 242 took a dump. Here's a tip though: The topmost bolts that connect the tcase to the transmission are really hard to get to. Take a 9/16 wrench, heat it up in the middle with a blowtorch, and bend it in a 90* angle. You now have a custom transfercase removal tool!

242 can be a PITA sometimes, blowd mine up real good, took it apart, every peice, no shavings, no nothing, put it back together to spec, readjusted everything, and wah lah, still didnt work.. peice of crap, id stick with a 231.