Swapping A T-Case?

Well i have a 99 XJ 4.0 with the NP242.

Thing does NOT shift into 4lo at all. I have the linkage cut out, i have a custom paddle on it, i have my transmission in neutral, and i can't for the life of me get the jeep into 4lo.

I think the T-case is shot, but i'm not sure how to tell. I don't know what would cause this. Could my sensor just be wrong?

Anyways, if it is shot, i was thinking about swapping in an NP231 (would rather have this than the 242.) (or do you think i should just find a working 242?)

How hard is it to swap a T-case? What would i have to undo/remove to do this? Is it straight-forward or is it more involved than i'm thinking it is?

Any insight would be great!

its pretty easy to swap. 8 ds bolts, and 6 mounring bolts

souske said:

its pretty easy to swap. 8 ds bolts, and 6 mounring bolts

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Any special way to pull it out or put another one back up?

What about compatibility? Any clue on what 231 would bolt up to my XJ?

I'll get to searching in the meantime.

Kingkong0192 said:

Any special way to pull it out or put another one back up?

What about compatibility? Any clue on what 231 would bolt up to my XJ?

I'll get to searching in the meantime.

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Roughly center it on a floor jack and lift it up. One of the easiest drive train items to remove and install. The jack is only really needed since it is awkward to hold in the air with one hand and thread on the nuts.

Anything from a 1996 to 2001 XJ, 1997 to 2006 TJ, and 1996 to 1998 ZJ. The only item you need to look out for is the input shaft length, but generally all of those years will be the 0.840" long input shaft. I put a NP242 from a 1998 ZJ in my 2004 LJ in December.

If you disconnect your shift linkage, you should be able to get underneath, and shift the TC into 4 low manually. It should go all the way to its internal stop, and then run in 4 low. The sensor could, of course, be bad, but until you have confirmed that the shift is occurring properly you can't tell. It's a common problem in conventional linkages that if it goes out of adjustment, 4 low is the first thing to stop working. Try the linkage off and put it on grass or a dirt road. If it doesn't go into 4 low with the linkage off, the TC is your problem.

Matthew Currie said:

If you disconnect your shift linkage, you should be able to get underneath, and shift the TC into 4 low manually. It should go all the way to its internal stop, and then run in 4 low. The sensor could, of course, be bad, but until you have confirmed that the shift is occurring properly you can't tell. It's a common problem in conventional linkages that if it goes out of adjustment, 4 low is the first thing to stop working. Try the linkage off and put it on grass or a dirt road. If it doesn't go into 4 low with the linkage off, the TC is your problem.

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Going to go try this now.

What do you mean by " It should go all the way to its internal stop, and then run in 4 low."? Are you saying i have to do something special to get it into 4lo?

I've heard you need to have the tranny in neutral and be rolling like 2-3 MPH to get the case into 4 lo. How would i manage this if i need to be under the jeep to get it into 4lo?

Kingkong0192 said:

Going to go try this now.

What do you mean by " It should go all the way to its internal stop, and then run in 4 low."? Are you saying i have to do something special to get it into 4lo?

I've heard you need to have the tranny in neutral and be rolling like 2-3 MPH to get the case into 4 lo. How would i manage this if i need to be under the jeep to get it into 4lo?

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No, I actually meant the opposite, perhaps poorly put. If you push the lever on the TC all the way, it goes no further, and there's a detent, and that's 4 lo. If you put the trans. in neutral, it should go in all right without movement. It's the specified first step in adjusting the linkage, and I've never had a problem getting it in.
At worst you might have to give the vehicle a wiggle. If you think there might be a problem in the TC, leave it in 2 high until you get under, then count the detents as you shift it. You should be able to feel the detent as each setting is hit.

I actually think the case is good.

Can someone confirm if this sounds normal? This is what the lights show on my dash when i click it one by one. It's a 242.

2WD (No Lights.)
Full Time
Part Time
No Light (I'm assuming Neutral.)
Part Time.

Is there no 4lo light? I could of sworn there was. Once it's in part time after the no light, it's impossible to turn the shifter down anymore with an adjustable wrench. That's as far as it'll go. (I didn't attempt to roll the vehicle, but the tranny is in neutral.)

Part time light should be on in 4L. When was the last time you changed your fluid?

I never had a 242, but at least on the 95 for which I still have the owner's manual, there was no 4 lo light, only full and part time lights, and your sequence is correct. If you put it on grass or gravel and drive in 4 low and it works right, I'd say you're fine.

Johnnie Walker said:

Part time light should be on in 4L. When was the last time you changed your fluid?

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I'd be embarrassed to tell you. I've owned the jeep since about 95,000 miles, and there are 118,000 miles on it now, and i've never changed it along with the tranny fluid.

I know i should really get on that.

Matthew Currie said:

I never had a 242, but at least on the 95 for which I still have the owner's manual, there was no 4 lo light, only full and part time lights, and your sequence is correct. If you put it on grass or gravel and drive in 4 low and it works right, I'd say you're fine.

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I can't go drive it on the grass, as there is no head in the jeep. I've been waiting for like two weeks for Levines to ship in my head, and i'm starting to get frustrated with them.

Currently working on rebuilding the 242 linkage and simplifying it.

While you're waiting for the head, you might as well get a jack and jack up one end, and see what happens when you turn some driveshafts. If it's going into 4WD part time, they should lock together, so if you jack up one front wheel, you should be able to turn it only a short time before it runs out of play and stops.

Matthew Currie said:

While you're waiting for the head, you might as well get a jack and jack up one end, and see what happens when you turn some driveshafts. If it's going into 4WD part time, they should lock together, so if you jack up one front wheel, you should be able to turn it only a short time before it runs out of play and stops.

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I have the front driveshaft out. I didn't even think to try to spin it to see if the front yoke is engaged.

Ill put it into what I think is neutral and if I can freespin the front yoke ill know its in neutral. Ill then put it in what I think is 4lo. If I can't spin the front yoke then I know there 4lo.

Thanks!

Hoping my head comes in today.

Well IF you plan on parting ways with your 242 I might be interested. I am wanting a 242 equipped late model XJ, and thus if I find one with the 231 I want to keep the 231 for the current DD Late model, in it, as I like the 231 better off road, and I want the ability for the full time at a later time. Sounds like you found your issue. Definitely change the case fluid. I learned a $600 lesson on my last '94 231 case where a PO neglected to change or even check fluid level, and I dang near drove the chain through the case. It goes to show that even though we know a lot about our rigs, we don't always know everything, hell I'm still learning.....

Jeff

Bumping my old thread. Going to swap out the T-case tomorrow and i need the jeep to be working again by the weekend. Sorry for the amount of pictures, but it will make things easier for me to describe.

My plan of attack is to remove the front and rear driveshafts, remove the linkage and sensors, use a floorjack and center it on the T-case and jack it up until there is a slight pressure on it. Remove all the bolts and drop the case.

Put new case on the jack, jack it up, re-bolt, attach linkage, shafts, etc, be done. Am i missing something?

I bought an NP242 T-case. It's out of a 93 cherokee. It's 23 splined - I counted. It has a Rubicon Express Hack N' Tap on it.

I currently have a 1999 XJ with a NP242 in it.

I was given a front XJ driveshaft to go with the case, and i think it will work. I just replaced the centering ball, and the three U-joints on the shaft.

Am i missing something? Anything i should know? Tips/tricks

Thanks for putting up with my constant questions. Haha.

Ignore the shape of the driveshaft. It's an old picture and i've since re-done it.

fresh fluid before install? speaking of fluid, what is the recommended fluid for 242 t-cases, anyone know?

Sidewinder CC said:

The fluid call up for the 242 is Dexron II or ATF Plus, type 7176, which are both dino juices. The call up for the 231 is Dexron II or ATF+3, type 7176. The ATF+3 had more friction modifiers than the original ATF Plus 7176 but is still basically a dino juice - not like ATF+4, which is now a synthetic ATF with max friction modifiers.

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I'm going to change out the fluid as well. I think it calls for 3 quarts but normally only takes like 1.5 quarts.

I just need to figure out if my method of attack will work and whether or not my combo will bolt in.

well, that leads to a new post for meh then... GL on your swap~