So I found a guy who has a 231 TC for sale. He just had a SYE installed but he got rid of his Jeep. His Jeep had an AX15 in it. Mine has an AW4 auto in it. Researching some it looks like it will work but I just want to make sure mounting isn't different between manual and auto.

 

Mounting isn't different, but shaft size and number of splines might be.
What year is the transfer case out of?

 

You can always just transfer the SYE to your 231, assuming your not replacing it cause its damaged.