I have a 1998 cherokee sport with a NP231 TC that I would like to reduce the 4 Lo range to 4:1 as opposed to 2.72:1 stock, without re-gearing. From my research, I’ve found that Terflex produced a low range kit previously but now is discontinued. Any ideas and/or experience creating a low range conversion without re-gearing axles??

 

the Tereflex worked, but could not be driven at highway speeds. But you can get what is called a 231 doubler. It adds a planetary reduction ahead of the one in the 231. There are several versions that use a cut down 231 case, but this one looks to be the cleanest

http://www.northwestfab.com/NWF-Eco-...se_p_2403.html

 

that northwest fab kit looks pretty neat, and not really a bad price.
but, you could always find a used 241 case out of a rubicon, or go with the ever so popular 231/300 doubler setup. this is the best option, but not too many are building the doubler kits anymore. one guy i know is staang's fab in burlington, ontario, canada. he has made many, and a few guys i know run his setup with great results.
i have two d300 kits at the ready, just need to find another decent 231 (i accidentally tossed a low mileage 231 in the scrap bin). the 231 needs to be cut down, and an aluminum block off plate welded in place, for the 300 to bolt to, but in the end, you will have two added 4x4 shifters to play with. and with the proper gearing, you can get a pretty decent crawl ratio with a 713:1 low gear.

google np231/d300 doubler staangs fab