Anyone ever install a NP242JHD in a XJ? I think I read that they have different input spline counts, but there's adapters for everything. My 242J broke and I'm trying to figure out my options. Thanks in advance!

 

I would put an NP231 in it.

 

I've read that a lot. I'm not really interested in a 231. My jeep never sees offroad so a 242 is fine. I'm more so interested in the compatibility of the 242jhd

 

From what I'm reading online, the JHD is a WJ transfer case more commonly known as a 242HD. The only problem I see with it is there's no provisions for a speedometer. There is one that's local to me now has a SYE kit already on it so I'm not worried about the spline count. Is there a housing from another transfer case that will fit this case that will add a provision for the speedo and still allow the SYE kit to bolt back up? I read that the 231, 242, and 249 input shafts are swappable, but are any of the speedo housings also swappable? Thanks in advance!

 

Im guessing the original reason to the post is simply because of this comment right here... Your current case is bad and because that 242hd case is nearby - Will this one work instead of something more direct? Well you kinda have your answer - sure with the right input shaft it will work but at the drawback of no speedo. No to my knowledge you cannot just swap rear housing because in that also you would need to add a speedo gear to the mix as well. Im sure the idea of "while im at it maybe i'll upgrade as well" hence the hd case - well depending on who you talk to the 242 tcase is more prone to failure vs the 231 - your wheeling intentions or aside from this point, a 231 tcase will be brought up simply because they are less prone to failure vs the 242 and also more plentiful as well.

If you do settle on going with the 231 - i dont know what year xj your playing with but if its 95 and older go ahead and find yourself a 231 from a 96+ donor - those tcase will have a sealed output shaft vs the 95- older which have a slip seal that will leak when the driveshaft is removed.

My last note/question if your jeep see's no offroad use at all then why is another tcase with an SYE kit installed on it a benefit to you??

 

That is a good observation and great facts! I also have a 242AMG from a humvee available to me. I thought about this because of the added benefits (the whole might as well upgrade comment) but there is no 2 wheel drive option in those transfer cases; so with it only seeing highway use it seems useless.

I really would like to keep the 242 platform. As you mentioned I don't go offloading, I do however would like to improve my XJ with offroad capabilities while keeping a stock look. I do like to explore my options and mod my Jeep and in doing so, I tend to take an unconventional approach. I'm mainly looking to see how far I can Frankenstein a 242 🤣

 

Alright so as mentioned before, the 242HD from a WJ that is near me has the bolt on slip yoke eliminator kit already on it. I've read online that 32 spline 242AMG transfer cases have 4 bolt tail cones on them. If I buy the WJ HD case, will the rear retainer housing bolt up to both the transfer case and the SYE kit and allow me to use my factory speedo gear? Pictures for reference.



NP242JHD case that I have available to me


HMMWV NP242AMG transfer case with the 4 bolt rear retainer housing with the speedometer gear provision

In a perfect world, I would try to add 2 wheel drive to a AMG transfer case but that's not realistically feasible for whats it's worth. But if I can do this "simple" mod instead, I would be much more comfortable doing it. I'm sure not too many people on here have had much experience with the HMMWV transfer cases, but if anyone knows this specific question for sure, it would solve a lot of things for a lot of future people.

The aftermarket for 242's is pretty scarce and a lot of people and probably too afraid to do a "hack and tap." Hell if it was as simple as throwing a WJ's HD transfer case into a XJ, and sandwiching a HMMWV rear housing in-between that and a bolt on SYE, then maybe there would be a larger market to reproducing HMMWV rear housings!

Anyways, any information in the compatibility of these parts would be amazing!

 

Also, if anyone has any ideas for a different, cheaper, more plentiful housing instead of the AMG one, I'm all ears! 😁😁😁

 

I just realized I could have been thinking about this for nothing! Is the HD output shaft even cut to receive the speedo gear??? I should have thought of this earlier! I feel so stupid 😭

 

I wonder if the Advanced Adapters HD SYE shaft and housing will work.

You'll have to pry the 242 from my cold, dead hands...

I want that AMG242 !!!!

 

I'm trying to get buy with spending as little as possible. If I already have a HD available to me with the sye on it, I'd hate to have to spend more on the shaft and housing. Plus the description for the shown HD case says it won't go into gear so I think I'll already have to buy some internals. I'm hoping I can swap whatever is broken from my 242j.

 

Might want to check this thread out: https://www.naxja.org/forum/showthre...1114207&page=4

^^^ he did the swap with an AX15 to boot. That's on my to-do list down the road, as well.

 

IIRC the shaft receives a slip on worm gear that is held in place by pressure of a bearing on the tai shaft

 

That is 100% correct! At least for the 242J and the 242AMG, but since there was never a speedo provision on the HD, I'm not sure if thats the case. If I get clear info on if the WJ 242HD is cut for the worm gear, I'll buy the HD case with the SYE kit, and the AMG rear bearing housing housing today and go from there. If anyone doesn't really know if it is already cut, I'll have to do more research on it.

Also, it appears it has the Iron Rock Offroad SYE kit, but I'm not sure if it has the aftermarket shaft on it or not. The guy who owns it bought it as is, and didn't install it so he doesn't know.

Basically, I'm trying to predict what the probability is that I'll be able to do a straight swap, and if not what will have to be done in order to make it work, if it's even possible. The HD TC and the AMG housing will cost me roughly $550. Which isn't that bad considering that's the price of the SYE kit alone. But what I'm trying to avoid is buying it all and none of it working and I'm back to square one with less money and more useless parts. Thanks again for everyone commenting and helping me on this epic quest to "simply" fix my jeep 🤣🤣

 

I guess im still confused as to why the SYE is so critical for this? from the looks of your briarwood jeep - its completely stock. Don't see the demand for an HD SYE tcase for something stock that often -and by often i mean never. Usually these conversations or upgrades come later down the road after bigger tires/gears lifts etc. If what your ultimately after is stronger 242 tcase then why not find yourself a 231/233c and rob the wider chain from that? You can also rob the 6pt planetary from a 231D tcase compared your 242's original 3pt planetary