Lower T-case Gears or doubler for 242?

I have a '00 XJ which I think puts me in the NP242 case, right? I'm not at home so I can't check at the moment. If that's the case, isn't my only option for lower gears means either sending my case in to get machined or some kind of a splitter/doubler or full case replacement like an Atlas or D300?
I'm wondering what 242 owners do? I already have an investment in to an SYE so I would rather keep the investment if possible.

Let me know what you've done, heard, put on your wish list, etc! Thanks =)

Actually, after a moment's more thought, the restriction of being stuck that low is annoying unless all you do is go on the rocks. Instead, a doubler would be much more attractive. Does anyone know of one that would fit between the transmission and transfer case?

You could have a 231, so i would wait till i got home to check. I know my 97 has a 231 and my old jeep had a 242 in it, but that was a 89.

Most likely has a 231

242's came on the higher trim level XJ's... assuming the 2-door in your av is your rig, you most likely have a 231, as 2-doors tended to be sports.

Does your shifter have a "full time" position? If no then it's not a 242. The 242 wasn't year dependent. More like trim dependent as noted above. The 231 is a much more common T-Case.

Yep. 231. Any doublers for them?

Would it be smarter to find a 241 from a rubicon and have the flanges changed to 1310s? They come with stock SYE and 4:1 right? I read that some people find them for less than 1000 and that would be an improvement over the loud Tera kit and shorter than a doubler setup which is better on driveline angles. Right? If so, anyone know what years I should be looking for ?

You'd want one from a TJ rubicon so nothing newer than 2006. The np241j is a great option if you find one priced right. Most sellers think they're made of gold

IslanderOffRoad said:

You'd want one from a TJ rubicon so nothing newer than 2006. The np241j is a great option if you find one priced right. Most sellers think they're made of gold

Click to expand...

Why TJ? Input or bolt pattern?

What's in the JK Rubi's?

TJ's have speed sensor where as the JK's do not.

Looking at used car parts places online they want ~$1250 for an NP241J.

Another option I ran across is this:

http://ebay.to/1xevnsj

It's a gearbox doubler. Runs ~$1400 shipped w/ mounting bracket, cable shifter linkage, etc. That would provide more control over gearing and give a 2-lo.

The NP241J has 1330 yokes right? So I don't need to do an SYE on it, but I do need to get my hands on a couple 1310 yokes if I want to use my existing shafts without modification?

Any other cheaper alternatives?? haha.

If not, which would you do? gearbox doubler? NP241J? etc

Ugh. The used parts places want an average of $500 for core charge and want the same case in return. So, now that's a $1750 transfer case with 4:1 gears. What would you do if you were looking at dropping that kind of cash on this? Still go with the np241 or something else?

You are very close to an atlas at that point. I would do that

The down side of any custom transfer case is that it means floor board modifications, probably loosing parts or all of a center console, etc. Argh.

you are pretty much at the point where your next upgrades are no longer budget-friendly. the cheapest route looks like getting a 241J and selling your 231 to off-set the core charge. i dont know much about the 241 but it's safe to assume it may be longer than your 231 so you may run into d/shaft length issues.
the next step i'd choose beyond that would be an Atlas, and then a front axle upgrade with deeper gears.

spinaldex said:

The down side of any custom transfer case is that it means floor board modifications, probably loosing parts or all of a center console, etc. Argh.

Click to expand...

You'll need floor board mods for the doubler kit as well + DS's.

An atlas starts getting pretty competitive at that point. I would love to have a 4 spd personally.

I'm going to be upgrading to a D44 front here in a couple weeks. I was hoping to also invest in a t-case gearing solution at the same time. I can drop $2000 on a solution.

Current solutions seem to be:

- NP231J Rubicon 4:1 Case
- Underdrive + D300 Flip
- Atlas II
- 231 + D300 Double Case
- 231 + Tera Low

Some thoughts on the above:

- Due to the lower horsepower of the 4.0, the fact that I have a light foot, I don't know if going for an Atlas makes sense. If I could save money by getting an NP241J, the end effect would be the same .. lower gearing, 2 settings (hi/lo), etc.

- There's something attractive about going with the underdrive or dual t-case setups in that you get 2 different lows and a high. Having a standard 1:1 on the highway, but being able to get yourself reasonably low for trail riding and then really low for rock crawling is very cool.

- The 231 + Tera Low has overall horrible feedback from everyone. Noisy, weak, price is close to many of the above options by the time you factory in wanting to beef up the 231 with better input/output shafts and chains, etc.

It seems that a dual case setup would be the best bang for buck from what I've seen. Underdrives run $1500, a D300 a couple hundred dollars, and labor/machine work would seem to bring it to around $2k. That would be the same as going with my 231, getting one of the adapters on Pirate for $500 and then mating it to a Dana 300.

Here's the problem:

- I don't have the tools or experience to pull that off. Brake jobs, tune-ups, bolt on suspensions, etc are the easy stuff. When it gets to this level, I want help. I've called a half-dozen shops around here and no one had a clue what I was talking about.

Which means, if I can't get a doubler setup because I can't find anyone who can help, then I'll need to go with a 241J, even if it isn't my dream solution, because it's something I or any shop can figure out.

I first went with a 241OR to replace my 231. Worked well, required a bit of massaging to the floor, due to my AC-15 being for a TJ, and clocking the T-case near flat to the "frame" rails.

The 4:1 was great for slow stuff, but there were a number of times when it would be nice to have the 2.78:1 for some of the faster trails.

So, I took the plunge and added a Black Box 2.7:1 in front of the 241OR. I will tell you, this was not a cheap nor easy solution. Massive floor rework, new belly pan with mounts for the trans and doubler, mods to the console to accommodate the new shifter.

On the other hand, I love the set up. I have 2.78:1 when I need it, 4:1 and 10.88:1, which is almost useless. I have 2 Low in both the 2.78 and 4:1 range. The 241OR has a Terralow 2 Low kit in it.

In hindsight, would an Atlas 4 speed have been cheaper? Maybe. But it has it's own share of mods required, and I couldn't have done it incrementally.

David Bricker / SYR

I'm really leaning on the 241J regardless of price after talking to many people and reading things here. The fact that its a bolt-on without modifications to the tunnel is a huge deal.

Why don't people put the 4:1 case in 4-High when not on the rocks?