leak

[mjtjnj]

:fs1:

 

Dammit. Replaced my noisy, 21 spline np231 transfer case with a quiet(er) 21 spline NP231. The crossmember was all wet after a little driving, so I checked the O ring on the speedometer gear housing and it was ok. Replaced the fill and drain bolts and gaskets (everything was wet, so no idea where it was coming from). There seemed to be too much fluid in the transfer case -- I filled it on the incline -- so I parked it level and let it drain to the bottom of the fill hole. Take her for a good drive, and come back and it's dripping again. The linkage is even wet, so it's coming from up higher.

 

I parked it for the day, I'm done, but any ideas? The mated transmission-transfer case surface is machined, so no RTV or gasket needed, at least I've never used one. Should I tighten up the nuts holding the case to the tranny? Maybe I didn't get them equally tight all around. I *GUESS* the used case I got could have a crack, I didn't go over it with a fine-toothed comb. Just looking for some ideas before I have a trans guy I know put it up on the lift.

 

 

Thanks

Tom

[Geonovast]

The surface between the trans and t-case doesn't use a gasket because there should be no fluid in there. If there is, you've got a leak on the trans output shaft seal or the t-case input shaft seal. If it's still coming from higher up, you might try the T-case breather.

[mjtjnj]

Thanks for the reply. Breather ought to be easy enough to check, I'll make sure the hose didn't slip off. I would assume that if it's the input or output shaft leaking, it would leak the trans fluid, and not the ATF from the transfer case?

[Geonovast]

You didn't specify if you had a manual or automatic.

 

It would be helpful if you'd put the basic info of your rig in your signature. :thumbsup:

[mjtjnj]

Sorry, it's an 87 2.5/AX-5.

 

It doesn't smell like ATF, which is what the transfer case is filled with.

[Geonovast]

Next place I would look is the back of the valve cover.

[mjtjnj]

...so my concern is that if it was something simple, like the breather, it would be ATF leaking; I would guess that the input/output seals - there are two? -- would leak the Synchromesh I filled the tranny with

[mjtjnj]

Valve cover is bone dry. I just put in a "good" used transfer case, then the leak started. Unfortunately, it seems like I'm going to have to pull it again.

[mjtjnj]

After replacing my noisy NP 231 with a leaky one, my next obvious question is, can I use a late model NP231 from late 90s/early 2000s XJ/TJ? My AX-5 is already out of a 2000 XJ, so I think the answer is yes.

[Geonovast]

As long as it was from behind an AX-4 or AX-5, yes. The 231s behind the AW-4 and BA 10/5 were a different length shaft, and the later AW-4s and AX-15s are 23 spline.. and a different length.

[mjtjnj]

I know about the spline count, I'm more concerned about the speed sensor, linkage (not included at most boneyards), the disconnect, and the yokes from a newer case being able to be "retro fitted" to my 87 setup. I had a 2001 TJ and I thought I remembered the rear shaft having a boot on it??

[Geonovast]

The ones with the boot will be a sealed output, and require a different length rear driveshaft. The 231 wasn't used until 87, so you won't have to worry about the front CV flange vs the yoke for a u-joint or different size hole for the speed sender. Anything 87-96ish should work fine.

[mjtjnj]

That's what I was concerned about! It is so difficult finding something that old that isn't shot, unless you get lucky and find one someone rebuilt. Maybe I should just pull it and change the seals....ugh.