Grand Cherokee transfer case swap

[Mitchen]

I think this probably belongs in modified tech,
and sorry in advanced for anything dumb in this.

My buddy just bought a 94 jeep grand Cherokee with about a 5 inch lift on 32's V8
it has the all time 4x4 transfer case with 4hi n and 4lo. no 2hi option.

he decided to wheel it the day he got it and ended up getting stuck so i had to get him out. and the tire had come off the bead and was flat. He had no hi lift or spare. This was definitely a bad decision on my part but he said he didnt care so i let him put my 33" (his is a 32) full size spare on his jeep (against my advice to just leave it for the night). its an entirely different tire. had him drive it home doing 20MPH the whole way on back roads and park it at my place. he decided to not listen to my advice and drive on the bigger tire befor i could get the wheel with a bent lip fixed and tire back on it. (valve stem broke off also)

tire and wheel are now fixed and back on. but sense he was driving with that stupid 33 on there the transfercase is making a rattling sound. we know its not the diff and i am almost positive it is the transfercase. a buddy told me its the chain inside the transfercase which probably got slacked out somehow. so now it is allegedly loose and causing the rattling.

My buddy wants to just get a junkyard NP231 and swap it in so he has a better case and possibly fix the rattling sound.

AS far as i can tell it is a straight swap. but i am not entirely sure so if im wrong steer me in the right direction.

any help would be appreciated.

Thanks,
Mitch

 

[Begster]

Swapping out the 249 transfercase on the Grand Cherokees is a pretty common occurrence. Here is a write up that involves a 242 transfercase, but should be essentially the same.

http://jeephorizons.com/tech/tcase.html

 

[1990heepxj]

id assume the 231 will just bolt right up no need to swap the internal front to rear differential due to the 231 not even using one

 

[old_man]

Make sure and match the input spline counts. The Grands came with 231s/242s/249s as valid options.

Do some web searching. If you have the computer with the display, you can move some jumpers to make it display correctly for each different tcase type.

Getting a speedo to work can be interesting. I went from 249 to a 242 and had to pull the gear and some parts from the old unit and put them in the new case. On the one I swapped, I had to crack the case and swap the planetaries to get the right spline count. From start to finish, it was a 4 hour job.

 

[Mitchen]

well i looked at the link that begster posted and searched some other sites. everywhere i have seen said a straight swap to a nv242 is pretty simple hardest part is swapping the planetary gears from the old t case to the new one. and bolting in the 242 with the swapped planetary gear.

are the t cases the same size? or will we need to get matching drivelines for a 242? also do i need to get all the t case shifter linkage with it? the websites slightly explained it but i didnt understand exactly if the original linkage would work.
junkyard said they would sell any grand cherokee t case for 150$ if we pull it.

Thanks,
Mitch