32RH output leak nightmare!

[Beachhead]

Last year, I rebuilt my transfer case and replaced the output shaft seal on the transmission (32RH). After which all leaks were gone for several months and it was fine, until I was in an accident, tub swap has been done, and then the leaks returned. Both in the transfer case out of the case split, and from where it looks like was the output shaft seal.

We pulled the transfer case, opened it up and resealed. Also put a new seal on the transmission output shaft.
Earlier today we put the transfer case back up, I let it sit for about an hour with no fluid in it, and the leak from the mating surface returned.
I thought maybe it was just remnants that was splashed into the space between the two, I wiped it off and filled the transfer case.

I continued to check throughout the afternoon, and the leak persists. The transfer case isn't leaking anymore, just the mating surface to the transmission.
I've wiped it off, I come back an hour later and there it is again. Several hours and there's a drip forming.

I am at wits end here and I don't know what to do. There were no apparent cracks in the transmission, everything looked fine, the transfer case went in smoothly on install.

I know there is that extended seal that someone will mention if I were to have a shorter input shaft... But, it is not a short input shaft, and even if that was the case. I did this seal fix last year and it went for several months without leaking, so I don't see how that could be a cause.

(I also wanted to add to this, way back when I originally rebuilt the transfer case, it had a TeraLow unit in it, which I removed because it was messed up. The mating surface between the transfercase and transmission was completely sealed with RTV when I bought the Jeep, the weep hole is also plugged. I removed all the RTV between the mating surface but I didn't notice the weep hole was plugged until today.)

Any advice would be helpful! Thanks.

 

[freedom_in_4low]

How is the surface of your t case input gear? Is there any groove where the seal rides? That short input gear seal kit may be of some use for you by moving the seal onto a "fresh" section of shaft.

 

[hear]

When you say transmission mating surface, you mean the t-case to extension housing surface, right? You don't mean transmission case to extension housing? Because that surface requires a gasket, and also some of the bolt holes pass into the transmission case and need to have thread sealant on them.

Assuming we're talking about the t-case to extension housing mating, if it's leaking there you possibly have 2 problems. First is that your seal isn't sealing, and second that your mating surfaces aren't mating well enough. Although I don't know to what extent those surfaces should seal; the extension housing between the seal & the t-case input should pretty much be dry and the weep hole should prvent fluid from ever getting to the mating surface (I think). Any fluid coming out the weep hole is fluid that got past the tranny output seal or the t-case input seal. Did you lube up the seal before you installed the t-case? Is it possible you booger'd up the seal while you were mating them? It's also fishy that the leak started after your wreck. I wonder if more things got torqued than you realized?

If it started leaking before you put fluid into the t-case, then it must be coming from the transmission side, but then you filled it back up so we can't really say which side it's coming from. You'll probably end up replacing the output seal before this is all said and done, but before you do, double check the seal ID against the t-case input shaft.

Also my internal LLM can't parse this:

Both in the transfer case out of the case split, and from where it looks like was the output shaft seal.

 

[Beachhead]

How is the surface of your t case input gear? Is there any groove where the seal rides? That short input gear seal kit may be of some use for you by moving the seal onto a "fresh" section of shaft.

Surface is good, no groove or marring. There are witness marks where the seal has rubbed on it, but no sign of damage to the shaft.

 

[Beachhead]

When you say transmission mating surface, you mean the t-case to extension housing surface, right? You don't mean transmission case to extension housing? Because that surface requires a gasket, and also some of the bolt holes pass into the transmission case and need to have thread sealant on them.

Assuming we're talking about the t-case to extension housing mating, if it's leaking there you possibly have 2 problems. First is that your seal isn't sealing, and second that your mating surfaces aren't mating well enough. Although I don't know to what extent those surfaces should seal; the extension housing between the seal & the t-case input should pretty much be dry and the weep hole should prvent fluid from ever getting to the mating surface (I think). Any fluid coming out the weep hole is fluid that got past the tranny output seal or the t-case input seal. Did you lube up the seal before you installed the t-case? Is it possible you booger'd up the seal while you were mating them? It's also fishy that the leak started after your wreck. I wonder if more things got torqued than you realized?

If it started leaking before you put fluid into the t-case, then it must be coming from the transmission side, but then you filled it back up so we can't really say which side it's coming from. You'll probably end up replacing the output seal before this is all said and done, but before you do, double check the seal ID against the t-case input shaft.

Also my internal LLM can't parse this:

Mating surface: Referring to where the transfer case housing touches the transmission housing. I'm almost certain there is not supposed to be a gasket there, i went through this last time and I've read around on the forums and in the service manual, and there is no gasket there. Aftermarket ones are sold but its not a factory component.

My understanding is that the two shafts interlocking with the combination of the oil seals creates a seal thus not needing a gasket.

The threadlocker I wasnt aware of. There was no atf coming out of the bolt holes after removing the transfer case though.

We put some atf on the seal before installing, and used a pretty good seal driver, didnt just hammer it in. It went in fairly smooth, no issues. I suppose its possible we screwed it up but ive had rougher seal installs that worked fine.

Regarding that last part. My transfer case was also leaking where it splits open, the rtv sealed "split" between the case halves. Opened that up, resealed it, and it no longer leaks.

Photo attached for reference. You can see the leak at the t-case/transmission connection point.

 

[hear]

I think you mis-read what I wrote.

The transmission/extension housing is where you need the gasket & thread sealer.

The extension housing/t-case does not need a seal or gasket, because in general no fluid should be in that cavity.


The leak is definitely at the latter. The question is which side is it coming from? Transmission output seal or t-case input seal? I don't see how it's not one of those 2 things.

 

[Beachhead]

I think you mis-read what I wrote.

The transmission/extension housing is where you need the gasket & thread sealer.

The extension housing/t-case does not need a seal or gasket, because in general no fluid should be in that cavity.


The leak is definitely at the latter. The question is which side is it coming from? Transmission output seal or t-case input seal? I don't see how it's not one of those 2 things.

I have a spare transfer case input shaft from my old unit, so I think i'm going to take the transfer case off again and then stick that shaft on there and see if it creates a seal properly, then i'll be able to clearly see where the leak is coming from. Best idea I can come up with right now.

 

[freedom_in_4low]

I have a spare transfer case input shaft from my old unit, so I think i'm going to take the transfer case off again and then stick that shaft on there and see if it creates a seal properly, then i'll be able to clearly see where the leak is coming from. Best idea I can come up with right now.

maybe while you're at it. don't put any oil in the transfer case and let it sit for a few days. If it leaks again you know it's coming from the transmission, if it doesn't leak until you fill the transfer case, then...

 

[Beachhead]

Other than the drain tube, the transfer case should be a completely sealed unit, right? So if I remove it still full of fluid, it shouldn't leak?

 

[hear]

Other than the drain tube, the transfer case should be a completely sealed unit, right? So if I remove it still full of fluid, it shouldn't leak?

There's a seal on the input shaft, right?

I have a spare transfer case input shaft from my old unit, so I think i'm going to take the transfer case off again and then stick that shaft on there and see if it creates a seal properly, then i'll be able to clearly see where the leak is coming from. Best idea I can come up with right now.

You mean disassemble it and just stick the input shaft onto the transmission output shaft? I love this idea.

 

[Beachhead]

Took the transfer case off while full, stuck the spare shaft in there and confirmed it was leaking from the transmission from the new seal, on the painted exterior of the seal. Not the rubber interior.

So, got a napa brand seal, greased it up and put it in. Napa seal is much tighter on the inside and outside than the timken, much harder to install.

Its been a few hours and can confirm no leaks. So tomorrow I'll be the t-case back on and hopefully it stays that way.

Napa seal for the output shaft from now on for me though, timken gets an F.

Photos show napa seal (green one) and timken seal (red)

 

[hear]

As long as you remembered to grease the lip before you put the transfer case back in, I'm willing to bet you've got this solved!

 

[Beachhead]

Well after installing the napa seal, overnight it leaked again. So i've decided that i'm just done with it. I frosted the outside of the seal with RTV and if that helps some, great, if not, screw it. I guess my transmission will just leak. The leak is significantly less than with the timkin seal, so i'll just check the fluid at a regular basis. Out of ideas.

 

[hear]

oh, I guess I missed that it's leaking from the "seat" and not the seal lip itself. I generally don't rtv the outer edge of a seal, but in this case I might use a little more than usual, and specifically something that can cure in the presence of ATF.