swapping transfer cases

I have two 1988 Cherokees. One with a five speed and a np231, the other with an automatic and a np242. Can I swap the 231 over to the auto and vice versa? I know that the spline count is the same (21), but are the input shaft lengths the same? Any other problems I might encounter? I was thinking I might have to swap the driveshafts also, but I can't tell by just looking at them.

There are some reports of different input gear lengths. Flush and long. But I am unsure of the differences between the 242 and the 231 in that respect. The manual and auto are a little different in length IIRC. So the Driveshafts woudl have to be swapped too I think. Well at least the front one would.

I'd say the input shaft length would be different...the 242 being about 1/2" too short. It'll bolt in sure enough (the 242 in place of the 231) but you'll have <1/2" of spline engagement, and won't have a seal against the trans output area, and will leak gear oil out of the trans. I believe you can buy a spacer to add the necessary length to fit the 231 in place of the 242, though, so you could swap it in place of the 242.

Best bet is to pull both and eyeball the input shaft length on both.
I've got a perfectly good 231 from behind an AW4 I can't use to mate to my AX5 for just this very reason..........
HTH,
Jeff