Tranny Case Q

Jeeper4life · **Posted:** Tue Feb 26, 2013 4:14 am

TheBlueKJ wrote:

dgeist wrote:

no-one appears to have mentioned it, but you likely have an NP/NV231 or NP/NV242 transfer case. There are only a couple variations used on the KJs, and most of the gas models have the first one. To be sure, find the ID tag on the back of the case (usually to the left of the rear output shaft) and clean/read it. Command-trac refers to the series of transfer cases that have 4HI/2Hi/Neutral/4Lo option (i.e. the 231). Selectrac refers to the family of cases that added a center differential for a "full-time-4wd" option (i.e. i.e 242).

Assuming you're correct in your diagnosis, knowing which case it is makes all the difference. The "output shaft seal" is what you want, I believe, and depending on the model, should be pretty easy to remove and replace. Not sure if you need to slide the seal off the shaft or the other way around. It might depend on what's covered up by that boot (i.e. can you remove the slip-yoke from the shaft to allow the seal to slide off).

Here's what a tag looks like:

Dan

I know for a fact I have the 231 t-case. Now I'm just wondering how hard it is to replace the seal. I'm hoping it's what you said with just removing the slip yoke and sliding the seal off. i asked one of the techs at work what they thought (I work at pepboys) and he said I need to rebuild the t-case or buy another (wtf?)

That guy shouldn't be working at pep boys if thats the kind of advice he is giving people...Should be a easy job...Might want to invest in a seal puller maybe. They aren't expensive..

TheBlueKJ · **Posted:** Tue Feb 26, 2013 8:32 am

Alright and I've already got a seal puller so that parts covered. Now I just need to go about getting the new seal.

dgeist · **Posted:** Tue Feb 26, 2013 11:57 am

TheBlueKJ wrote:

I know for a fact I have the 231 t-case. Now I'm just wondering how hard it is to replace the seal. I'm hoping it's what you said with just removing the slip yoke and sliding the seal off. i asked one of the techs at work what they thought (I work at pepboys) and he said I need to rebuild the t-case or buy another (wtf?)

I think the tech may be wrong:
http://www.naxja.org/forum/showthread.php?t=926934
http://www.jeepforum.com/forum/f37/np231-tail-shaft-leak-fix-82091/
http://www.youtube.com/watch?v=qCZuWKh-kEo

I'm guessing you can do it pretty easily in the matter of an hour or so (taking your time).

Dan

TheBlueKJ · **Posted:** Tue Feb 26, 2013 7:29 pm

I looked at the link on JeepForum and they're replacing a different seal. The seal that's leaking on mine is directly on the t-case. If you look at the pic there's the boot then where the drive shaft goes into the t-case, and beneath that part there is the seal that is leaking directly on the t-case.

dgeist · **Posted:** Wed Feb 27, 2013 10:05 am

So, are you saying between the rear half cover of the t-case and the cone-shaped aluminum section that houses the output shaft seal is the leak location (i.e. where those two sections are bolted together)?

If so, then it's a little more work. There are lots of howtos for slip-yoke-eliminator kits that show you how to take that section off. It's sealed with high-temp RTV (or possibly not since it's leaking). Also a fairly easy job. I don't believe the output shaft has to be removed at all for that cone to be slipped off and re-sealed, possible a few spring clips and re-orienting the transmission fluid pickup tube, though (which most howtos discuss).

Dan

Jeeper4life · **Posted:** Wed Feb 27, 2013 3:17 pm

You shouldn't have to pull the whole out put shaft out of the T-case. I would guess just pull the driveshaft and the "cone" part of the t-case. Then reseal. You might have a couple snap rings to undo, so a good pair of snap ring pilers would be good to have. Yeah I think the pump and tube sits in that section but its not hard to take the tube off and then hook it back up.

TheBlueKJ · **Posted:** Wed Feb 27, 2013 4:01 pm

Ok so it shouldn't be that much harder then. So I loosen up the 4 bolts pull off the cone a little bit clean up where the sealent is and reseal and put back together?

Jeeper4life · **Posted:** Thu Feb 28, 2013 1:41 am

TheBlueKJ wrote:

Ok so it shouldn't be that much harder then. So I loosen up the 4 bolts pull off the cone a little bit clean up where the sealent is and reseal and put back together?

Thats pretty much how it should go I think, just take care when taking off the cone part to not scratch the surface mating areas when you pry on it to get it off. Oh and drain the t-case first otherwise your gonna get a crap ton of fluid come spilling out at once..

TheBlueKJ · **Posted:** Thu Feb 28, 2013 9:44 am

Yea I kinda figured that would happen so I'm gonna be changing the fluid at the same time i fix the seal.

TheBlueKJ · **Posted:** Sat Mar 02, 2013 8:05 pm

Does anyone know if the rear retainer uses a gasket or just plain rtv?

Tranny Case Q

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