So I started with a 99 xj with ax15 2wd, swaped it out for a ax15(4wd from a 96xj) and mated it with a 231j that I put a SYE on, my t-case will not go into 4hi or 2wd now, so I read maybe its because I didn't have my driveshaft in to let it move a little bit allowing me to shift it threw the gears of my transfercase, well it didn't work, now when I let off the clutch in first gear I hear a clunk and popping noise but I cannot move forward or backwards, please help, if you need any other info to help me let me know. thanks again!!

Did it shift when not bolted up ?

Did shift rod move in hole in rear cover freely ?

If you have this plug remove and look inside....

Just took the cap off and the fork is not completely lined up, it did shift while it was off, im still curious why is was grinding and poping and wouldn't allow me to move. Thanks for the insight thus far!!

Did instruction say you needed to cut shaft to length ?

Could be gears not lined up correctly. Shaft need to move freely in hole and not contact the plug.

Mine had similar issue i drilled whole in case slightly bigger but not into threads for plug cured all issues

thanks for all the help, I made sure the shaft was the correct length not sure why it wouldn't be lined up correctly seems like with the case together it would have to be positioned right, looks like imam crack it open again!

Quality control sucks....

So I have it apart, again...and even with the back of the case off as soon as I put the mode fork in its like it binds up and wont shift into 4hi or 2wd, pull the fork out and its good to shift through all the gears, I checked and made sure the mode fork was all lined up and it was... not sure what the heck it going on but I need some more help

Seen this...

Yeah thats what i watched when building mine. I think i found the culprit correct me if im wring but my 94 23 spline ax15 would require a 23 spline short input shaft i believe the input shaft on my 231j is a long shaft which would be why everything is binding up