NP249 to NP231 Swap

Evilidea

New Member
Location
Mt. View Wyoming
Hello,
I am new to 4x4's and also new to these forums. I have a '97 Grand Cherokee Orvis with a shot np249 t-case, and I bought a np231 off KSL under the impression it was a np249. Both of these t-cases are 23 spline and I have read some how to's on the web but they left me feeling uneasy about it. Can anyone here give me a link to good step by steps on how to swap these. Any help would be greatly appreciated.
 

Brett

Meat-Hippy
It's realllllllly easy. The only concern you're going to have is if the input gears are the same length. If you have both case's out, just do a visual check of how much the input gear is sticking out from the case. If they are the same, you don't even need to split the case's. Other than that, it's 6 nuts on the front of the transfer case to unbolt it from the transmission. Remove the shifter linkage as well, plus the breather and whatever wires are connected to the case. Swap in the 231 and you're set. Reverse the steps.
 

Evilidea

New Member
Location
Mt. View Wyoming
Well,
We had both out and the np231 wouldnt fit into place. I will dbl check the length tomarrow as I only checked the spline count. Am I correct that if they are not the same length I need to swap the input gears? Also, do I need to get something like the novak shifter linkage or can my old one connect to it? Is there a way to tell if my np249's input gear is shot without doing all that work? Last question would be... is there anyway to rewire the command console to work when doing this swap?
 

gijohn40

too poor to wheel... :(
Location
Layton, Utah
I think that JP magazine had and article on this swap not to long ago... they found that they had to make a new shift lever which they did but they also said that you can buy the novak or advance adapters shift linkage kit and it worked the same... otherwise it was a direct swap as long as the input shaft was the same...
 

Badger

I am the Brute squad
Location
South Salt Lake
Just go to a junkyard and yank the shifters out of anything with 231. I have heard that some people get away with readjusting the stock shifters.
 

grandmaster

Let the build Re-begin
Location
St. George, Utah
I did this swap in my grand about 2 months ago. I recommend pulling the 231 appart regardless of if you need to or not, clean it all up and reassemble it. I had to swap input gears, and i added a tera 2 low. From there it will basically bolt up. I was able to get the command center thing to work, but not like you expect... I bought the 4x4 selector thing (kind of looks like a spark plug, but has a button(ball) on one end and a plug on the other) and screw it in. I can't remember which wires go to which, but if you would like i can look when i get a second. So now when im in 2wd it doesn't show anything, 4wd it shows all 4 wheels light up, 4low all 4 wheels light up (you should be able to tell the difference between 4 high and 4 low) and in 2 low it doesnt show anything. If this doesn't help there is a writeup , that should answer most of your questions. http://www.mallcrawlin.com/forum/showthread.php?t=2781
www.kevinsoffroad.com also has one.
 

Evilidea

New Member
Location
Mt. View Wyoming
Well,
I have gotten some good info here and I have read several other how to's. I think we will give it a go here soon and I hope to be back out at the hill climbs within a week or so. The only thing I am still concerned about is the input gears cut, but I guess I will see soon enough. If it is not a matching cut does anyone know where I might find one, because Wyoming has nothing as far as junkyards etc, SLC is closer than any real cities in Wy :rofl:.
 

Evilidea

New Member
Location
Mt. View Wyoming
Well I need to do the input gear swap. I have all the bolts and snap rings removed from outside of case and I can get the case split about 3-4" but it refuses to come all the way apart. Am I missing something? The 249 will not come fully apart and I haven't cracked the 231 yet.
 

Evilidea

New Member
Location
Mt. View Wyoming
Well,
This has become a pain. With the limited amount of time I have had to do the work I have been Jeepless for almost a month :mad:
I got the 249 split and lucky me the gear cuts were the same. The 231 slipped back together slick as snot but now the gears are bound, I am not sure if I got something wrong with the shift/range fork or what but it is not spinning. I hope to get a few hours to crack it apart again and see this weekend but man I tell you this has become a big pain. Anyway just thought I would update you guys, any info would be helpful and I hope to get it done and out into the Uintas before too much snow hits us up here.
 

Evilidea

New Member
Location
Mt. View Wyoming
Almost done with this project. I am only having issues getting the Novak shift linkage I went with to shift through all the gears. There are alot of different positions you can mount that in and I just can't seem to find the one that fits my Grand. Everything else seems to be doing what it is suppose to though. Anyway if any one is familiar with the Novak linkage installation and you got some info to share, I'll take any help I can get as I will be burried in snow real soon up here and do not have shelter to work in:-\
 

Evilidea

New Member
Location
Mt. View Wyoming
OK, project from hell almost complete. So, whats my problem now:D? The rear driveshaft is a little too long. Does anyone know if a driveshaft from any other model will work or if not what length I need to have made for this. Again this is a '97 Grand with a 2000 NP231 T-case.
 

Bart

Registered User
Location
Arm Utah
Well, the nice thing about a driveshaft being too long is it can be cut and welded with little expense. Just take it to your closest driveline place.
 
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