I'm a bit confused about this, you can't have duel transfer cases in a xj because it is to long and don't have enough drive shaft right? Well I'm in the middle of swapping my auto tranny for a Manuel and need a longer drive line so why can't I duel it now? And besides how are you able to do a duel transfer case in a tj or something when there drive line is a foot long? Can some one please explain this to me.

 

You can use a doubler kit, just search for 231 doubler and you will find what you need.
You could always install a Teralow kit or a TC out of Rubicon if you just want the 4:1 reduction.

 

I found the 231/241 doubler but everyone said its to long to fit? Are the full of crap or telling the truth

 

Not sure about that one, but I have seen a 231/231 and a 231/300 in an XJ, IIRC.

 

It will fit if you cut the floor and raise part of it to clear the doubler,Now a doubler is not for everyone.If you want a hardcore rock crawler get one if its more a daily driver/weekend toy i wouldn't use one.In your case swapping trans you can get away with just grabbing a stock stick driveshaft from a xj and bolt it in unless you have a sye then you need a front driveshaft or order one online.

 

Sorry I ment 231/231 typing this all on my phone. I found a guy here in town that can rebuild and balance my drive line for cheaper than buying one and was thinking since I'm getting drive lines made and have two 231s already why not. It not my daily driver it is MOSTLY just a trail rig I do drive it on the street from time to time. I was thinking this would be the best option for the next step of my jeep since its an all around rig I go from needing super low gears for rocks to gears for mud to cruising the sandy river banks so just one set gear ratio helps one but takes away from the other.

 

If I were going to do one, I'd do a 231/300 over a 231/231. Even then, it's still chain driven and I've seen several of them break and most people who build them soon ditch them in hopes of a better case. Get a 241or, 2 speed Atlas, or a Stak.

 

Isn't a 241 a chain driven case?

 

Yes. That was worded poorly. Essentially, don't build a doubler and just get one of those other option.

 

Although a 231/300 doubler should only cost about $800-900 so that would be a cheaper alternative to the Atlas or Stak. I think those 241or t cases can be had for around 1200 tho right?

Ive looked into a doubler to make my life easier since a 5 speed can be a chore when you only have 2.72:1 low range. Check out D.D. Machine for their 231/300 box4rocks kit.

 

Can't you put a black box on a 231? Or is that just for the d300...?
Either way, I wouldn't do a doubler.
I'm in the process of rebuilding and swapping a 231 where my 242 is. If I had to do it again( if time allowed) I would buy a d300 and the flip ring to put it under my jeep. There is a good thread on pirate I think it was about putting a 300 in an xj.
Look into the terra low kit for the 231 as well.
There's many other options for you to get to that 4.1:1 other than a doubler

 

If i had the money http://offroaddesign.com/catalog/Magnum%20Box.htm

 

Would rather have a 2 speed atlas.