Okay, I didn't spend much time at the shop today, but I need to remove the output shaft housing from my 95YJ NP231 and put it on a 97 Cherokee NP231 T-case. I removed the five bolts and the speed sensor. I can pull back the housing about 1/2", then it stops. What is keeping me from removing the output shaft housing from my t-case in my 95YJ?

Is it stock or does it have a SYE?
If it's stock, pull the three bolts that hold the extension housing on the bearing retainer and remove the snap ring that is up against the bearing.

It is stock.
Thanks, I figured there was some sort of c-clip or snap ring retaining the output shaft.
I was really surprised with the difference between the NP231 for a YJ and the NP231 for a 97 Cherokee. The Cherokee doesn't have any sort of extension housing over the splined portion of the output shaft. There is a boot similar to a CV shaft that attaches with hose clamps to the output shaft and to the drive shaft. The Cherokee NP231 uses grease to lubricate the splines, where as the YJ 231 uses the oil in the T-case.
Also, my YJ t-case had Dexron Mercon fluid in it, while the Cherokee had what looked like 75W90 gear oil. Are both okay to use?

Both T-Cases use ATF.