OK, so I finally got around to pulling the transfer case off of my son's 94 Jeep Grand Cherokee Laredo (I6). I acquired a 231 transfer case off of a 92 Jeep Cherokee a while ago and did the spline count comparison this morning after I got the 249 down and out. That was a royal PITA with wind, rain and cold!

So here is a picture of the boy's jeep, as you can see the drive shaft is out and the front one is hanging. Yes I marked their position before I pulled them so I know how they align.


And here are the two transfer cases side by side. The 249 case was quite a bit heavier than the 231.


So, the next step will be to clean the donor 231 case. Based on reading several threads on the transfer I am pretty sure that the input shaft gearing is the same as the 249 had a January manufacture date on it so should be the early gear cut that is in the 92 231 case. When I pull them I will do the comparison as I will have to swap input shafts.

So, as I read through the write ups on doing the swap, some questions begged to be asked. Here they are.

1. "You do however NEED the shift tab from the transfer case you are swapping in, the long tab on the 249 will not work." Does anyone have a picture of this part? I am betting I can still find it on the donor vehicle at PnP if I know what I am looking for.

2. Shift indicator sensor, can I just pull the one off the donor vehicle and splice it in?

3. Front Axle shaft linkage. I recall reading that this would be an issue as the donor vehicle had a single U-Joint at the transfer case end of the front drive shaft and this Jeep has the double cardin type. How do I remedy this? I don't see how to resolve this in any of the write ups.

Those are my starting questions, I'm much more comfortable tearing down and rebuilding motors and 2wd suspensions so this is new territory for me. Any advice or help would be appreciated and, if you live in the Chesapeake, VA area, free beer and pizza is available to whoever has done this and wants to come over and help!

Steve Aki
US Army
Chesapeake, VA

 

Steve, both transfers will be 23 spline input, both should be early gearcut.. unless the XJ had a swap done at some point. Carefully look at the planetary gears and compare how tapered or flat the gear teeth are.. if they look the same your good to go with swapping it. The reason you need to swap is the ZJ input is longer..

93-95 I6 ZJ's with the 42RE: .840" 23 spline input (with collar)
92-95 XJ's: .750" 23 spline input


1- Look at the pic you posted, the shift tab is the long piece on the 249 that has the through bolt just next to the front driveshaft yoke.. the 231 pictured has none.

2- Cant help as i'm only familiar with the 242 swaps.

3- Your front driveshaft yokes are ujoint style.. non CV. The CV would be a round yoke.

Your most likely gonna need to swap transfer shift linkage, and possibly driveshafts for correct length. Also probably gonna need a ZJ specific 231 transfer shifter and bezel.. good luck on that one as the 231 ZJ was a rare one.

 

Thanks for the info. I think I have resolved the issue...for the most part.

 

Or at least he smiled upon me today!

So I headed off to PnP to find the adapter that Overland pointed out I needed. The 92 I pulled the original 231 Tcase from was gone...rats. So I stumbled around and found another Jeep Grand Cherokee Laredo AND, it was a 94. Well, she'll probably have a 249 case so won't be useful...or so I thought.

As I walked around her the transmission and transfer case were already out and on the ground, someone pulled the motor. Someone was also kind enough to wipe the Tcase tag down so I could see what type it was. Wait, dare I believe this?! Can it be true?! Doth mine eyes deceive that of the weary wanderer in search of the holy Tcase?! Nay! Tis true! Thy Tcase is a 231!

I kinda stood there for a moment, in shock, giddy, light headed...then I jumped into action, went out and got my tools from the back of my little Geo Tracker and pulled the case. The adapter however was nowhere to be found. Now, based on what I understand, the 249 adapter is too long. This being said, a hacksaw and drill should be able to fix this issue. We shall see.

I got the case home and checked input shaft lengths on the 249 and my new 231 acquisition, YES!! SAME LENGTH! So, I'll clean up the new case and open her up for inspection and do a final comparison of input shaft sizes to the 249 to make absolutely sure but God finally took pity on me and threw me a bone...thanks man!

 

Excellent..

And you grabbed the transfercase shift lever assembly, bezel and linkage correct?

 

Nope. They were pretty torn up from the guy who dropped the tranny and transfer case to begin with. However, since this is off of the exact same year and model as my son's Jeep, it shouldn't be an issue. I did get a bezel from the original 92 donor tho so got that covered. I will have to mod the adapter that goes from the transfer case to the linkage. I'll tackle that after I get everything else done.

 

So I got around to dismantling the Transfer case for an inspection and clean up. So far all the gears are good. The damn seals on the front and rear output and input shafts are a bear though.



I hope to finish cleaning everything up this week then getting it put back together and installed so I can work through the shift linkage issue. And, were on our way!

 

Well, I finally got the 231 put back together. I had to tear it down again once as I forgot to put in a retaining ring. Got that sorted and she is now ready for installation. I was fortunate enough to actually find a place in Arkansas that had a brand new 231 shift adapter in stock so that is on its way.

Now I have to extract the broken bolt for the transmission support. Wound up breaking off part of a drill bit in the bolt so will have to cut the bolt down almost flush with the frame and re-drill. This time however I picked up a set of left hand drill bits. Hopefully, she'll spin out when I start to re-drill the bolt. I'll hit it with some heat and cold first before I start to see if I can loosen her up a bit. I'm hoping to get that done today.

I plan on selling the other 231 Transfer case since I didn't use it and I'll put it up for sale in the Buy, Sell, Trade forum later today after I get some pictures of the Tcase to upload. The transfer case was about 100 times simpler than rebuilding my Porsche 901 Gearbox!

My biggest enemy has been time. The first three weeks of a new class are always brutal and I am on the podium pretty much every day for our first instructional module. We transitioned this week to our second module so my fellow instructor can take that over with me in support which frees a lot of time up for me. Goal is to have everything buttoned up by Saturday. We'll see how that goes, as we would say when I was an infantryman, 'no plan survives first contact.'

 

231 will sell quick haha. Im getting ready to swap a 242, I got linkage and new bezel so everything will just bolt right in (don't get me started on gear cuts and all that crap, i got lucky that's all i can say).

 

Well, after crappy weather and other issues I finally got around to putting the Tcase in this morning. Things would be easier with two people but I tend to be left to my own devices.

So, after a failed attempt using a second jack I just did what all Army guys do, brute force! I basically set the Tcase on my case and did a one arm bench press and lifted the Tcase into position while guiding it into the stud holes with the other hand. Good thing the sucker is only about 75 lbs which is fairly light. It is awkward though.

I did have to run out to the Jeep dealer to pick up the bushing for the shift lever, that was easy to get in but the connecting rod to to the lever that goes through that bushing is a bit of a pain!

So, what do I have left. Lets see.

1. Adjust 4WD selection lever.
2. Clean up and re-install axle shafts.
3. Make electrical connections in cabin.
4. Fill Tcase and tranny with new fluid.
5. Add power steering fluid, its a bit low.
6. Take her out for a test drive and, if all is well, get her aligned.

I should be able to get at least half of these things done tomorrow IF the wife doesn't already have plans for me. We shall see.

 

HA,HA!! The hardest part of handling a t/case is it doesn't have a convenient center of balance. When I did the one on my Chevy 4x4 (NP208), I built a nest with a steel plate and 4 pieces of 1/2" threaded rod to bolt to my floor jack. after I got it just about high enough, the freaking jack rolled over sideways! Luckily I didn't break anything.

 

No, no it doesn't have a good CG. Building a nest is way too much work, bench pressing it was easier...relatively speaking.

 

So I got the axle shaft's installed without incident. I decided to check the PS system before I moved on to the other things. Well, wouldn't ya know it, I had to replace both the high pressure and return hoses. That took a bit of time so I didn't get around to adjusting the Tcase shift linkage. I'll get to that today. I also need to make sure I torque everything down before I start that though.

I'll tackle the electrical connection last as that is relatively minor. I am hoping that I can potentially take it out for a test drive tonight if I get the linkage adjusted without incident. I saw in another forum that the proper way to do this is to put the rear up on jacks and put the Tcase into N. Align the lever, tighten then check that the rear wheels spin freely while the drive selector is in park?

Gotta do a bit more research before I tackle this later today.

 

Yeah, but I'm a retired 69 year old Navy guy, not an in shape Army guy!

I think you've got the adjustment scheme right. It's basically what you'd do with a 242. The 242 however has detents so you have to press down on the lever to go to neutral and 4lo.

 

Isn't round a shape? Not nearly as in shape as I used to be 15 years ago, still stronger now than I ever was as an 18 year old. I'll hit 50 in two years, lets see if I can stay in shape! I will not ever, ever run again after I retire though, I'd rather spend an hour swimming and two hours in the gym than any amount of time running!

I did find a drawing of relative position of the shift lever for a 231 that I will use to help me find the proper positions. A detent would probably be easier to work with.