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NP231 swap

What year? Some years may or may not have vacuum disconnect changes, I forget.

Other than that, the shift gate and bezel, and maybe the lever and linkage. You might not get your full time/part time lights working or might have to do some wiring work and install a bulb in the cluster.
 
What year? Some years may or may not have vacuum disconnect changes, I forget..

the vacuum disconnect does not have anything to do with the transfercase, with but the axle. thats where the disconnect is. pulling the lever on the 231 puts it in 4wd, the disconnect locks the axle.

but, most 231's were 21 splined when used with the disconnect.

so, the real question is what year 242???
 
the vacuum disconnect does not have anything to do with the transfercase, with but the axle. thats where the disconnect is. pulling the lever on the 231 puts it in 4wd, the disconnect locks the axle.

Right, except that 242-equipped XJs never had a vacuum disconnect from the factory. Depending on the year of the XJ involved in the swap it could be an issue, since there may be a vacuum disconnect unit on the axle that'll need to be removed / blocked off.

so, the real question is what year 242???

And what year XJ is it going into? IIRC, '87-'90 were 21-spline, whereas '91-up were 23-spline.
 
not to hijack, but i am also thinking of doing the swap from an 89 242 21 spline. my issue is that my transmissions (aw4) front pump is making some serious noise. so i thought i would upgrade to a 23 spline transmission from a 91+. i know i can still find a 242 in the 23 spline version, but from what ive read on here, the 231 is the way to go. so my question would be, what years can i get a transmission/231 from a donor vehicle that would be an easy swap into an 89? also mine does not have the disconnect since it HAD the antilock system.
 
Into an 89, I think you CAN use anything from a 97 down, preferably 95 down. 98 and up you can also use, but you will end up swapping the output speed sensor rotor and extension housing. Stick with a 95 down if you can because of the output slip yoke design change in 96.
 
not to hijack, but i am also thinking of doing the swap from an 89 242 21 spline. my issue is that my transmissions (aw4) front pump is making some serious noise. so i thought i would upgrade to a 23 spline transmission from a 91+. i know i can still find a 242 in the 23 spline version, but from what ive read on here, the 231 is the way to go. so my question would be, what years can i get a transmission/231 from a donor vehicle that would be an easy swap into an 89? also mine does not have the disconnect since it HAD the antilock system.

the anitlock had nothing to do with the disconnect, you didnt have the disconnect because of the 242 case.

as for 23 splined trans and transfercase, the issue become the tcu. im not sure of the exact years to use as i have a manual trans in my 89.
 
Oh yeah. Another thing, I forget if you will need to splice on your original connector for the wiring harness if you go past a certain year, which I'm not certain of - they changed a lot of connectors on the wiring harness in the years surrounding the OBD I/II split (95/96/97) and I don't know if the tranny harness connector was included. The solenoids and other junk in the transmission are compatible up to 97 (or 95 for the transfer case output shaft) however.
 
from what ive read on here, the 231 is the way to go

There are a lot more upgrade options for the 231 than the 242. Having said that: I've run both at different times and wouldn't trade my 242 out for a 231 - having an AWD mode in addition to 4WD is just too useful both on the trail and off. Is there a specific reason why you want to go to a 231?

so my question would be, what years can i get a transmission/231 from a donor vehicle that would be an easy swap into an 89? also mine does not have the disconnect since it HAD the antilock system.

IIRC, ABS had nothing to do with whether or not the axle had a vacuum disconnect or not. The presence of the NP231 or NP242 was the determining factor.
 
ok thanks for clearing up the abs/242 thing. i was just reading the "which axle do i have" thread on the frequently askend question forum, and it said "all ABS and 242 eqiuped XJs came with the non disco" so i assumed it was either not both.
as for why swap to 231? for no other reason than since i planned to get another trans, i figured to get the 23 spline, and from many posts ive read the prefered transfer case was the 231. i have no problem staying with the 242. i do however like the full sye available for the 231 with its upgraded shaft. though i have also read that the hack and tap version for the 242 has been very succesfully used. that said, am i going about this all wrong and just stick with my 21 spline and either find another trans or fix mine? the trans is working fine. just makes a serious whine in both drive and reverse. i figure the front pump is going to go south, though its been lasting. the prior owner drove it that way for over a year. i just planned to go to the JY at half price day and get a transmission and transfer case mated and just swap them out. most of the XJs in our yards right now were from the cash for clunkers program, so theres a good chance of getting a decent transmission since they had to drive in.
 
ok thanks for clearing up the abs/242 thing. i was just reading the "which axle do i have" thread on the frequently askend question forum, and it said "all ABS and 242 eqiuped XJs came with the non disco" so i assumed it was either not both.

Understood. FWIW, it's been a good while since I looked at a disconnect-era XJ with ABS, so could be wrong about that - but I don't think am.

as for why swap to 231? for no other reason than since i planned to get another trans, i figured to get the 23 spline, and from many posts ive read the prefered transfer case was the 231.

Going to 23 splines certainly makes sense. More:

i have no problem staying with the 242. i do however like the full sye available for the 231 with its upgraded shaft. though i have also read that the hack and tap version for the 242 has been very succesfully used.

This just came up a couple of days ago: there are full tailshaft SYEs for NP242s; I've had one in my XJ for around three years or so now. Granted, they're not as cheap as NP231 kits, but they are out there. See here for the early-design kit, and here for the late-design kit. Both of those include the driveshaft (which you'll need anyway), so with that factored in are fairly reasonable pricewise.

that said, am i going about this all wrong and just stick with my 21 spline and either find another trans or fix mine? the trans is working fine. just makes a serious whine in both drive and reverse.

Your call on that one - I get where you're coming from, but I'd address that issue before worrying about the transfer case since it a) sounds like a potential near-term reliability issue, and b) may end up dictating your transfer case / SYE choices to some extent.
 
May be cheaper to find a combo AW4/t-case
2stix, if you swap let me have your 242, lol.
 
Sorry for not mentioning my year i have a 96 inline 6 HO. My 242 is knocking in 4x4 in part and full and low but not 2 and all my u-joints are good i checked them. another thing is my front end squeals when going down the road, no clue why i checked my bearings and they are fine fluid is fine idk why though. and its only a constant squeal when going slow foot off the break, and when i am going fast it is intermittent.
 
so now my level has so much play it will kinda engage in part, full, and not really low. and i went to change the fluid and i checked it which i have not, and it was brown and black with dirt and metal shavings, it was not low though.
 
metal shavings are bad... really bad. Sounds like it may have been abused in a previous life.
 
yea i know that i have i bought it a year a go and never even thought about checking the fluid. which i will from now on. so can i do a 231 swap? or do i need to stick with the 242?
 
yea i know that i have i bought it a year a go and never even thought about checking the fluid. which i will from now on. so can i do a 231 swap? or do i need to stick with the 242?

Your call, but if I were in your shoes I'd stick with the NP242. Nothing wrong with the NP231, but I'm a fan of the full-time mode both on-road and off-.
 
yea i know that i have i bought it a year a go and never even thought about checking the fluid. which i will from now on. so can i do a 231 swap? or do i need to stick with the 242?

It really is a question of how you use your XJ.

Are you serious about offroading? If you are, and are going to put a lot of stress on the system, then I would get the NP231 and upgrade it with the wider chain upgrade: http://naxja.org/forum/showthread.php?t=965779&highlight=NP231+chain+upgrade. You can't do this with the NP242 due to the Full-time option.

Another thought is a SYE. There are lots of options for the NP231, and some are priced as low as $150. For the NP242 you have a couple of choices--a hack-n-tap or the Tom Woods setup. Hack-n-tap cheap, Tom Woods $400+ depending on the options.

If you are mostly commuting and not abusing things offroad then the NP242 is a good transfer case.

Of course, there will 25 replies by those that have abused their 242s, and 100s of stories by posters whose Uncle Billy Bob and 4th cousin Bubba always abuse their transfer cases and have never had any problems--First rule of internet posting, first liar doesn't stand a chance. :farmer:
 
i do quite a bit of offroading, and its my DD, I rather have a t-case that can do better for off road and has cheaper upgrades. my question is is it a complete bolt in?
 
If you do the swap, and make sure there are no spline issues, then all you will need is the t/case, you will probably want the shift linkage--there are some mods that work better--and the shift gates from under the center console as well as the shifter bezel. That should about do it.

If you can source the NP231D from a salvage yard you would get the wide chain setup and be ready to romp. I'm watching for one for myself.
 
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