I have a 2000 xj......im putting another np231 transfer case in it because mine is not working correctly.
I have a issue when it comes to getting my transfer case.

everytime i order one from this salvage yard, they are sending me a np231 its the right case....but on the rear of the case the output for the rear drivline has a long shaft with spline on the end of it.

My transfer case is open and has where the yoke goes in and the drivline connects to that yoke.

They have sent me to with the big long shafts attached with spline and that wont work with mine.

What is going on ??

 

sounds like yours has a sye on it. the one you are getting from the jy is factory with a slip yoke hook up.

 

so all the factory ones have that shaft with the spline on it ?

 

I would assume so considering a sye is an aftermarket add on. You could always transfer the sye to the other case if its still in good condition (if that seems to be the issue.

Remeber you can always post a pic, it will help others help you!

 

how hard is it to take the sye out and switch it over on the other transfer case .

 

Im not totally sure on that. I have never done one but i remember seeing a write up and a video of it somewhere.....search around here on sye installation, and google for the video.

 

if you could post a couple pics so we can see what you are working with, it would be a snap for someone to give you a simple solution. if it is in fact a sye in yours then they are not hard to do. if yours is already out and you have the replacement one then it should be as easy as opening them both up and moving the parts you need to the donor tc.

 

It is not hard. There are numerous write ups on it in 4WD mags and on NAXJA and Pirate. You will need basic tools and snap ring pliers to do it. Start from the back and work your way in.

 

Hi. I've been going through similar problems with jy tcases. It sounds like you're getting the np231 with a "live shaft" versus a tail cone (if you search on live shaft you should find some more info). Mine is a 1995 4.0 automatic and the original case had the tail cone output shaft assembly. I found that I could install the case with the live shaft but still need to get a dust boot for it. Keep us posted and good luck.
Bruce

 

As has already been confirmed, you have a slip yoke eliminator on your existing case, which replaces the slip yoke with a fixed yoke output that your rear drive shaft bolts up to. What you're getting from the junk yard is the stock slip yoke, which has the splines on it you described that slide into the back of the t-case. All you need to do is swap the SYE from your existing case to your replacement case. This can be done right under the jeep without taking the t-case out. Lots of writeups on it over on NAXJA, and probably one or two here on CF as well.

 

 

if your transfer case is stock, it will look like this:


if the one they are sending you looks like this (the long cone housing on the back) it is from an older model jeep:



and if the back end looks like this, then you have an SYE installed on your current one:

 

x2