231 > 242

 

The 231 gets more love because there are just so many of them out there. Remember was the only case available in a wrangler for a long, long time. Hence, all the easy upgrades available for it. But actually, the 242 has a larger front output shaft (32 spline), larger chain gears, and a fully gear driven limited slip for full-time usage. That same case, except for a larger 32 spline rear output is used in Military H1's, even the 10k heavy armored versions....behind a diesel....but only has 4hi/4L as shifting options.

The 242 isn't a bad case and will take as much abuse as a stock 231. But once you want to start modding it, SYE, larger chain, 4:1, etc......just stick with the 231.

Unless your hands on a H1 242 and switch out the gear selector with one from a 242j.

And if you have shifting problems with your 242j, you should tear it down and check the shift rails and fork pads. Which is common among all NV cases.

 

The 242 is a decent transfer case. I have the 242AMC it's went everywhere the guys with 231s have gone. The full time is a great option for areas like here that have a lot of sugar sand.

 

anyone know the input and output shaft spline, on a 231 j 93 XJ?

 

Welcome to the forum. Ill check my reference manual in about 30 min for ya and let ya know.

 

hey freegdr. what type of fluid goes in my 5 speed 95 model? any idea?

 

Go big or go home... AtlasII lol, I vote 231 as well.

 

Overpriced. Lol. It would be nice to have the old D20 or NP205 in our Xjs.

 

It would just be easier to go with the 231, so many more aftermarket upgrades to be had
just gotta point out that when the 242 is in fulltime both front and rear drive lines are engaged but the center diff is open.

 

As I said before, the 231 has a larger following because it was only option available in the wrangler for so long. In both cases they have the same rear from the factory. If either loose the rear output...the 242 is stronger, larger chain pulleys and larger output.

But as far as upgrades, you'll have to step up and pull parts from a 242AMG or a late, late model 242, and mod to fit in your 242J. No different that pulling larger parts from a 241 and 231D/C and putting them in a 231J. With the 231J, the aftermarkets done the work for you.

 

There is a sticky on here somewhere with the transfer case models and specs of each one.