249, 242 hybrid swaparoo

[v8zj]

Hi everyone! This is my first post for this forum, and I really wanted to thank everyone here who has written about doing a NV249 to NV242 swap. I wouldn't have gotten anywhere without your help!

Anyway, I did the swap with a 1994 ZJ NV242 4.0L into a 1995 ZJ Laredo with a 5.2L V-8. I ran into the gear cut change issue, and it was definitely frustrating--until I read on here about the hybrid T-case solution.

The main thing I wanted to add to the forum is the 1995 NV249 t-case and the 1994 NV242 t-case require absolutely no drilling or tapping or modification in any way to make them work. I used the front half of the 249 and the back half and all internals of the 242--perfect fit, and success the first time. Shift linkage bolted right up, and everything including the speedo gear works as advertised.

The only real problem I had was breaking down the 242--getting the shift forks off of the little notched shift dealie (hehe, technical terms only here) was a real pain. Make sure you have a nice crow/pry bar handy--it helps to have two people and some heavy gloves.

Also, make SURE you have a 12 point 10mm socket handy before you take the case apart...it's impossible to do with vice grips

Thanks again!

[DJJordache]

ok explain the 249/242 combo a little more. you only did this b/c of the input pitch issue or did you do it for the larger 249 chain and 249 chain gears? I think I read somehwhere it was possible to put the larger 249 chain and chain gears into a 242, I might try and do this on my brothers 90 242 since I have a ton of 249 spare parts from a 95 249. now you got me thinking about this...time for more reasearch

[v8zj]

The input sun gear from the I6 242 would not fit on the output shaft of my tranny--I needed the sun gear/input business from the 249. I originally tried swapping the whole sun gear assemblies, but no dice because of the gear pitch. So...I used the 249 front case half.

As far as the chain is concerned, the 249 chain is indeed larger, but I have no idea how you would make that business fit. The output gear for the front seems like it would be no problem, but as far as finding a way to drive it...I'd imagine you'd have a good bit of trouble with it. In all fairness, I didn't even consider this so I might be talking out my rear...but I would say you'd have a heck of a time making it happen.

If you do give it a shot and it works, please let me know! Definitely something I'm interested in doing.

L

[DJJordache]

hmmmm well I might try it or at least mock it up since I have a torn open 95 249 (took that input for my 2000 231) and a busted 90 242 just sittin in the garage and I would not have to worry about having a vehicle down. I'm pretty sure I heard about someone who did what I was talking about. I might try and mock it up this weekend if I get bored

[Jim311]

I wish you'd post some pics, because I just find this all hard to conceptualize in my head.

[v8zj]

I'm really sorry, but I don't have any pics. My intention of posting here was to mention the 95 249 and the 94 242 have identical front case halves, meaning you don't need to drill or plug anything (contrary to other posts on hybrid 249/242 t-cases).

The other thing I mentioned about breaking down the 242...the shift lever on the outside of the t-case rotates a sprocket/cam/slotted dealie on the inside of the t-case. The shift forks are actuated by a pin that sits in the sprocket's slot--getting them apart was the issue I had. Pry the crap out of it, but make sure it's with a good tool or you'll mangle the crap out of everything.

Sorry again about the lack of pics!

[rsl]

I'm really sorry, but I don't have any pics. My intention of posting here was to mention the 95 249 and the 94 242 have identical front case halves, meaning you don't need to drill or plug anything (contrary to other posts on hybrid 249/242 t-cases).

The other thing I mentioned about breaking down the 242...the shift lever on the outside of the t-case rotates a sprocket/cam/slotted dealie on the inside of the t-case. The shift forks are actuated by a pin that sits in the sprocket's slot--getting them apart was the issue I had. Pry the crap out of it, but make sure it's with a good tool or you'll mangle the crap out of everything.

Sorry again about the lack of pics!

That's why you have to drill a hole in the 249 case. It is to access the 242 low range shift fork rollpin. If you drill the hole you don't have to pry the crap out of everything and take a chance of bending something. You can use a #1 screw type extractor to pull and install the rollpin and everything slides apart easily.

Tapping the hole is optional, I didn't like the cheesy 2 bit rubber plug used on the 242 so I tapped mine for a 1/8" pipe plug.

BTW, I am the person that noticed the cases were the same when I ran into the gear cut problem when I put my 242 in.

[v8zj]

I definitely wasn't taking credit for figuring out the hybrid deal--I know there are multiple versions of both cases out there, and I just thought that maybe the 94 242 and the 95 249 were more identical than the ones you came across.

As far as the roll pin is concerned, I could see no way other than prying the thing apart--the whole assembly was one piece of metal, not so much a pin.

Just tryin to help...

[Jim311]

So do you think it only works with 242/249s, or will it work with 231s and 249s as well?

[DJJordache]

So do you think it only works with 242/249s, or will it work with 231s and 249s as well?

nope the case of the 231 is much more flat is height than the 242 or 249 oval housing shape

[Jim311]

I don't want to swap in a 242 though, so I guess I'm stuck trying to find a case that my input will fit into.

[MoonWorks]

Jim...What case do you have now a 249? I imagine that DJJordache will correct me if I'm wrong but why couldn't you swap your 249 input shaft out and into the 231 you want. These guys are talking about integrating cases...why would you really care about the case...just use the 231 case.

[Jim311]

Because my rig is a 96, and the 231 that I got for virtually nothing is out of a 90 YJ, so it's unlikely that the gear pitch will be correct.

[DJJordache]

yeah Jim did you ever get around to measuring the input length on yours? I think I read about someone whos 5.9L tcase input was the meduim .840 input don't remember who it was though, so MAYBE yours might be also and maybe the long one was just for the 93-95 46rh, maybe.....dunno for sure

edit I just thought of something, I'll check on something about the gear pitches as I just happen to have a 2000 231 input and a parts 1990 242 case I'll see if the 2000 input will slide into the 90 242 for ya=)

[ZJRuss]

Very enlightening thread, much good knowlege, thanks for shareing the wealth. Here's hoping your research and efforts reveal another swap option for the ZJ community.

[DJJordache]

ok Jim here is some info you might find interesting....with pics
OK I just got back in from the garage mixing and matching parts and let me clarify what they are first in these pics
a 2000 XJ 231 input with planetary
a 1990 XJ 242 input with planetary
a 1990 XJ 242 case
a 1995 ZJ 249 case
I took the input with its planetary (MEDIUM input length of .840" exposed but had a internal collar on the inside of the input) from the 1995 249 case and put it into my 2000 XJ 231 and it been perfect with no problems, later on this at the bottom.

First pic"
On the LEFT is the 2000 XJ 231 input with planetary that is the MEDIUM input length of .840" exposed
On the RIGHT is the 1990 XJ 242 input with planetary that is the SHORT input length of .750" exposed
NOTICE the larger lip on the base of the 231 input (LEFT)


This pic shows the a 1990 XJ 242 input with planetary in the 1995 ZJ 249 case and notice that the input gears are flush with the case gears. This combination can freely spin with no bad noises, and I would feel comforatble running a setup like this.


This pic is of the 2000 XJ 231 input with planetary in the 1990 XJ 242 case. NOTICE the gears DO NOT ride level because of that additional lip noted above on the 2000 XJ 231 input.


This also happens when I put the 2000 XJ 231 input with planetary in the 1995 ZJ 249 case


Here is another pic of the 2 cases side by side

kinda hard to see things in this one but the closeups above show the details. The inside of the 242 is super dirty b/c the full time dif blewup inside the case when my brother blew up his D35 and that in turn killed the 242 case.

one more thing that I ran into when I was swapping inputs in my current 2000 XJ 231 to install the input from the 95 ZJ 249.
I was planning on swapping just the inputs but when I took the 249 input and tried to put it into the 231 planetary I ran into the gear pitch difference issue and I could NOT get the 95 249 input into the 2000 231 planetary. I also, as a test, could NOT get the 2000 231 input into the 95 249 planetary. SO I tried the entire 95 249 input WITH ITS planetary and that fit just fine into the 2000 XJ 231 and it sat with the gears level and spun correctly and this combo has been fine for the last few thousand miles.

I know all that mixing and matching got kinda confusing but I hope I made sense


one more thing that additional lip might just be a later model thing you might have to open up your case and see.... or if anyone has pics of a 96-98 ZJ v8 tcase input post em up plz!

[Mr.BoJankels]

ok explain the 249/242 combo a little more. you only did this b/c of the input pitch issue or did you do it for the larger 249 chain and 249 chain gears? I think I read somehwhere it was possible to put the larger 249 chain and chain gears into a 242, I might try and do this on my brothers 90 242 since I have a ton of 249 spare parts from a 95 249. now you got me thinking about this...time for more reasearch

I have a spare 249 case as well, but from what I can remember, which isn't much I don't think you can just simply swap the larger 249 chain and gears to the 242???? but please look into it! I would love to make my 242 stronger, I know I'm going to stretch the shit out of the rinky dinky chain

[DJJordache]

yeah I'm going to but I have to wait til my brother comes back home for the thanksgiving break since he took some of the 249 guts b/c he thought they would be cool paper weights

[DJJordache]

hey Jim I just check one more thing in the parts lists I got from Dirk. I don't have a separate parts list for just a 96 ZJ but I do for a 97 ZJ and it says that the 4.0L, 5.2L and 5.9L all use the same input so your SHOULD be the medium input length... but I don't know for sure if it has that lip like the pic above. and FYI the input in the parts list for a 97ZJ 249 that I looked up is not the same as the one for the 2000XJ 231 but it is the same for a 2000XJ 242

[Jim311]

I think my brain is going to explode. Basically what I'm gathering is that I *probably* need a medium length input, and that I should either find a 96 or newer transfer case, or somehow get medium length input in the older gear cut?

[DJJordache]

I think my brain is going to explode.

ok basicly going on the idea that you *probably* already have the medium input it would be easiest to get another tcase that is 96-01 XJ 231/242 or 96-98 ZJ 242 and that would be bolt in, maybe have to change the rear driveshaft since these are external slip and not internal like your 249 don't know if there is a driveshaft length difference. FYI mine is from a 96-98 4.0L 42re 242 and is 31.5" ujoint center to ujoint center.

You cant get the early gear cut medium length since it only came in the 93-95 4.0L ZJ and those all have the internal collar inside the input, and will not slide onto your transmission output shaft on the 44re.

I don't think the gear cut is that big of a deal if you swap the entire planetary with the input and not just the input: since I could put a 95 input into a 2000 case and could also put a 90input into the 95case, but could not put the 2000 into a 95 or 90 just becasue of a lip length difference but it would have gone in all the way if it were not for that lip (as pictured above), but maybe the cases I have are just lucky

[Jim311]

You can order input shafts though, correct?

http://www.novak-adapt.com/knowledge/np231.htm

[DJJordache]

yeah but that page has not been updated in a while or something because it says that the medium is only the 93-95ZJ which is not true. the medium length is in some 93-98ZJ's and in some 96-01 XJ's depending on its engine trans configuration. Also look at the bottom of he Novak page there is no pic like the 2000XJ medium input narrow bearing late gear cut like mine above on the left. they only show the .75" and the 1.55"

[Jim311]

yeah but that page has not been updated in a while or something because it says that the medium is only the 93-95ZJ which is not true. the medium length is in some 93-98ZJ's and in some 96-01 XJ's depending on its engine trans configuration. Also look at the bottom of he Novak page there is no pic like the 2000XJ medium input narrow bearing late gear cut like mine above on the left. they only show the .75" and the 1.55"

I was *hoping* to use the YJ transfer case I've got, but it's looking like that won't work

[CurtisXWZJ]

I realize this is an incredibly old thread, but I was wondering if anyone ever managed to figure out if it is possible to put the 249 chain in a 242 case? I currently have a 242 that needs a chain/sprockets and my parts rig has a 249, but as I am still driving my DD I can't tear it down for experimentation.