Transfer case output seal, still leaking!

[Jared Jackson]

Need some suggestions, I am brainstorming while I am at work and I am not coming up with much.

My rear output seal on my transfer case was leaking... so we replaced the seal. Still leaking...

So i ordered a new seal and a new yoke, replaced those, still leaking.

There was no play from the yoke to the busing and the bushing passed a visual inspection by by father-in-law who is a transmission tech at a dealer (ASE master). I trust his eyeballs at this point.

When we put the new Dorman yoke on the driveshaft and put it back in the transfer case, it was a pretty tight fit!

What else could be causing this leak? defective parts maybe?

 

[Stokes1114]

Clogged vent tube? I would check that first.

 

[Jared Jackson]

Clogged vent tube? I would check that first.

I haven't noticed a vent tube on the transfer case yet...

 

[Stokes1114]

Well there is. Off the top, should be a hose running up to back side of engine block. If no hose then check where the vent hose attaches on top of the transfer case. That piece could be clogged as well. Common problem for it to get clogged and the pressure build up makes it leak through the output shaft or elsewhere.

 

[Jared Jackson]

Does the 241 (Manual shift) and the 243 (Electric shift) share the same extension housing?

Vent checked out.

I am debating ordering a new extension housing assembly with the new bushing and seal (just to cover my bases that mine is not warped or defective) and give that a shot. I already have a new yoke and seal, that didn't do the trick.

I know I can replace my bushing for cheaper, but I am not worried about cheap and would rather do this in my driveway with 4 bolts than have to figure out how to mess with getting that bushing out and in. I love bolt on stuff...

ACDelco 15665311 GM Original Equipment Automatic Transmission Case Rear Extension with Seal

 

[jdla140]

Does the 241 (Manual shift) and the 243 (Electric shift) share the same extension housing?

Vent checked out.

I am debating ordering a new extension housing assembly with the new bushing and seal (just to cover my bases that mine is not warped or defective) and give that a shot. I already have a new yoke and seal, that didn't do the trick.

I know I can replace my bushing for cheaper, but I am not worried about cheap and would rather do this in my driveway with 4 bolts than have to figure out how to mess with getting that bushing out and in. I love bolt on stuff...

ACDelco 15665311 GM Original Equipment Automatic Transmission Case Rear Extension with Seal

output housings are the same for a lot of NP transfer cases, as long as they have a 4 bolt pattern. Check fluid level, it's common for the input seal on the Tcase to let go and allow fluid from the trans to fill it, and then it will leak from the output shaft.

Is the fluid for sure coming from the seal? there should be a tiny little drain hole in the middle of the yoke, and when the splines wear out, you can get fluid coming from this hole. it will look exactly like an output seal leak. A common fix is to just plug that little hole with RTV.

Check fluid level, verify the vent isn't plugged, and verify that it's not coming from the hole in the yoke. if everything checks out, pull the driveshaft and make sure the slip yoke is in good shape. No rust, groove from old seals, etc. While you have the driveshaft off, take the output housing off and install a new bushing. It's a very common wear point. Replace the seal again and use the updated style if you haven't already, should have a little dust hat.

I really chased my tail on my 94 trying to get the output seal to quit leaking. My housing ended up having a slight crack in it that was allowing it to leak, it was on top and I couldn't see it. I've been told this isn't an uncommon occurrence. An output housing from a newer cherokee with a 231 worked fine for me. Hopefully you get it fixed!

 

[Jared Jackson]

It’s definitely leaking from the seal. This is a brand new dorman yoke and seal... only thing left is that bushing and there was 0 play between the slip yoke and bushing... we had to use a dead blow on the driveshaft to get it to seat into the extension housing... it was a tight fit!

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[Jared Jackson]

I pulled the fill plug on the transfer case and no fluid came out... I dipped my finger in there and it is right below that fill line. So... this tells me that there is no leak between the transmission and the transfer (filling the transfer) as some threads I have read suggested.

I thought we checked the vent on the transfer case, but it turns out that might not have been checked (I was working with someone else). I hopped under there ( the drivers side ) and I can see a rubber line extending from the transfer, to the transmission and over the transmission to the passengers side. It looks like it is zip tied with some factory wires. I believe this should be the vent hose (I have no idea what else it could be). Now I just need to find the other end!

 

[jdla140]

I pulled the fill plug on the transfer case and no fluid came out... I dipped my finger in there and it is right below that fill line. So... this tells me that there is no leak between the transmission and the transfer (filling the transfer) as some threads I have read suggested.

I thought we checked the vent on the transfer case, but it turns out that might not have been checked (I was working with someone else). I hopped under there ( the drivers side ) and I can see a rubber line extending from the transfer, to the transmission and over the transmission to the passengers side. It looks like it is zip tied with some factory wires. I believe this should be the vent hose (I have no idea what else it could be). Now I just need to find the other end!

I would replace the seal and bushing again, you definitely shouldn't have to use a hammer, it should slide right in smooth as butter. There's a chance that you messed up the seal pounding the shaft in. I like to put a little grease on the end of the slip yoke to protect the seal

 

[Jared Jackson]

I would replace the seal and bushing again, you definitely shouldn't have to use a hammer, it should slide right in smooth as butter. There's a chance that you messed up the seal pounding the shaft in. I like to put a little grease on the end of the slip yoke to protect the seal

It’s possible... the factory slip yoke “slipped” right off... the new dorman yoke (clunk fixer) did not slip right on... and we lubed it. I didn’t mean to sound like we beat it on as you drive down a railroad tie... just had to give it some taps at the rear to get it going back on. But you are right... never felt right to me having to do that.

But this tightness was after it had slipped over the shaft inside the t-case... so it wouldn’t have had any side to side motion... just in and out across the bushing.