I have a '99 cherokee sport with an np231..I'm having problems with my current t case and purchased a new (new to me anyway ) np231.. I'm wondering how difficult the swap is.what do I need to know

. And just fyi , the new case has a 23 spline input and 27 spline output shaft .. how do I determine what my current one has ?? Can I do it while its under my jeep or do I have to remove it ?? Any help would b appreciated .thanks

 

http://www.novak-adapt.com/knowledge...nput_gears.htm
that should help you

 

91 and up has 23 spline.
90 and down has 21 spline.

swapping out a t-case is very simple, but can be a pita at the same time.

you want to drop the crossmember and support the trans and lower it enough to get to the top 2 bolts. you will want a stubby 14mm or 9/16 wrench.

the nuts may come off, or the whole stud might come out. either or, it's simple but very heavy once you get the bolts out.
so be careful that it doesn't fall out and meet your face. lol.

 

So the output shaft which is 27 spline should just go right in with no problem?? My current tcase is from a '99 and the new one is out of a .'00 .

..and ok so jus remove the cross member and support the tranny.seems simple enough ..how many bolts will I need to remove ?? ..is there any speciam lube or locktite or anything like that ,that I will need to know ??

 

yes, they both should be 27 spline

i think there's 6 nuts/studs

no locktite needs to be used, no rtv just bolt up and go.

 

I just changed mine yesterday on mt 95 it was pretty simple, but can be a pain to get to a few nuts. I wish i would have had a ratchet wrench yesterday, that would have been a big help, but i did get it done either way.
Take both driveshafts off.
put a jack under tranny to support it.
Unbolt the crossmember.
unplug speedometer plug, dash light plug, and vacuum hose.
Lower the jack down enough to get some levrage to pry out the linkage, or i just took my whole linkage assemby off, made it easier.
Unbolt the 6 bolts, and just push that sucker off.
Reassembly is pretty much the same but an extra set of hands will come in handy while trying to line up the new tcase with the holes and the shaft.
Best of luck too you and your project!

 

Well cool, this doesn't seem as hard as I thought I would be .. I will take all of your guys' advice .. only thing us I can't get around to doing it untill maybe next Monday ,so that sucks.. but whenever I do I will definitely have an extra set of hands so it should go pretty smooth ..will post the results asap

 

TIP! : first drain your automatic pan with atf, otherwise it will be very messy when you remove the case, Red showers. You can reuse the atf again or better replace the same quantity with new atf before you start the engine the first time.
Enjoy the swap !

 

Thnx for the tip ..will do

 

replace seals also rear of tranny front of tc while your iin there

 

i've never heard of this happening...

 

Where can I get this ??

 

Yes it did happen to me, even they had warned me before

 

Well I finally switched out the tcase today.wasn't that difficult..only got to do sum light testing tho.can't wait to really try it out ..thanks for all the advice everyone.

 

Glad all went well man