Transfer case interchangeability

I have a '96 XJ with a a NP231 TC and I was thinking of swapping it with a 242.
I dropped by a salvage yard to talk to the guy, he showed me in his books that only a TC from a '96 can be used in a '96.
It seems that '95 and below are interchangeable (till '91 Ithink) and also '97-2001. A '96 is all by itself.
What's the deal? Is there something different about the '96?

I'm not sure about the years, but I need your transfer case if your willing to sell it. I have an np242, but it's out of a 88xj

jephs422 said:

I'm not sure about the years, but I need your transfer case if your willing to sell it. I have an np242, but it's out of a 88xj

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If I can figure out what fits my XJ, I'd be interested.
I don't think that yours would directly fit mine and vise versa, but the only difference may be the imput shaft. There seem to be quite a few shafts that
would fit the 231.
Is your 242 on or off the Jeep?

it's on right now. I'll pull it as soon as I get a buyer, and find a replacement

Input shaft splines are either 21 or 23.Auto trans models have 23 spline.Before 96 the slip yoke went into the case,leaks fluid if you pull drive shaft.96 and after have sealed case,slip yoke outside of case no fluid leak without DS.
So you need any 242 case from a 96 and later,this will match the DS and the input splines,not sure about the LEGNTH of the DS though.
Also the selector bezel on the consoul will need to be changed.
HTH
Wayne

Wayne Sihler said:

Input shaft splines are either 21 or 23.Auto trans models have 23 spline.Before 96 the slip yoke went into the case,leaks fluid if you pull drive shaft.96 and after have sealed case,slip yoke outside of case no fluid leak without DS.
So you need any 242 case from a 96 and later,this will match the DS and the input splines,not sure about the LEGNTH of the DS though.
Also the selector bezel on the consoul will need to be changed.
HTH
Wayne

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I found a web page about TCs that shows not only different number of splines but also a number of input shaft lengths and even two styles of teeth on the input shaft gear. I need a TC that will bolt on and use the same driveshafts, no extra parts with the exception of the shift gate.
If I have to buy one or more driveshafts, or input shafts, the cost is more than I am willing to pay.
Thanks for the info, I need to make sure before I put the money down, it would save me money not to mention the work and getting stuck with the Jeep in the garage till I solve my parts problem.