Seal/Gasket Between Transfer Case & Transmission

[YukonRog]

I know there's a gasket that goes between the two and have read that it's supposed to be a "dry" seal. Yet mine was covered on both sides with a gray material that's similar if not actually RTV. I've read to not use RTV. But most when separated have some ATF come out. And Permatex makes some sealants specifically for transmissions and transfer cases. I was buying materials for my TC rebuild and install and I bought some. Instructions read "Assemble and tighten until it starts to squeeze out then let it cure for an hour and then do the final torque. Let cure 24 hrs before adding fluid."
So some say use it, some say don't. Mine had it on it. What should I do?

 

[Bill 1960]

Dry in the sense there should be no ATF in that space. The transmission output shaft seal keeps trans fluid out of that space. The transfer case input shaft seal keeps transfer case fluid out. So the cavity should be dry inside.

I don’t think it matters whether you use sealant on that gasket or install it dry, I think it’s there to keep dirt away from the seals. Perhaps someone with the shop manual handy will chime in.

 

[YukonRog]

Dry in the sense there should be no ATF in that space. The transmission output shaft seal keeps trans fluid out of that space. The transfer case input shaft seal keeps transfer case fluid out. So the cavity should be dry inside.

I don’t think it matters whether you use sealant on that gasket or install it dry, I think it’s there to keep dirt away from the seals. Perhaps someone with the shop manual handy will chime in.

Thanks for chiming in Bill 1960. I read "dry" as in nothing on the gasket. But like I said, mine had something on it. And I would think there would be no fluid from the transmission in there but everyone that pulls the TC says fluid comes out. And it did. My transmission is a remanufactured one with only 7500miles on it so you'd think they would have at least replaced that rear seal.

 

[George B]

Just put it in without any sealant added.

 

[YukonRog]

Just put it in without any sealant added.

That's what I'm reading but I'm questioning why a "professional" shop would use something. OCD kicking in....LOL!

 

[Bill 1960]

That's what I'm reading but I'm questioning why a "professional" shop would use something. OCD kicking in....LOL!

Probably to keep a leaking seal contained so you’d not know it was there.

When I had my transmission replaced it subsequently leaked at exactly that spot. Which, to give credit to the dealer doing the installation, they immediately noticed. The transfer case needed a new front seal.

 

[YukonRog]

Probably to keep a leaking seal contained so you’d not know it was there.

When I had my transmission replaced it subsequently leaked at exactly that spot. Which, to give credit to the dealer doing the installation, they immediately noticed. The transfer case needed a new front seal.

Well the transfer case has a new seal going in and from what I read all the transmissions leak a little.

 

[rockola1971]

Well the transfer case has a new seal going in and from what I read all the transmissions leak a little.

They all dont leak a little. Only the ones that were improperly put together or put together with worn parts. The tranny output shaft and Tcase input shaft seal are there to keep respective fluid in. They will not prevent fluid from one or the other from entering. A leaking Tranny output shaft seal will eventually cause the Tcase to overfill and blow out its vent.

 

[YukonRog]

Okay so I have to replace the rear transmission seal then. It's leaking. Does the adapter for the Transfer Case have to come off the transmission? I can't find any YouTube videos or any written directions on my 1st look around on the old InterWeb. Is there one seal, or more? I need pictures! LOL! More work I guess. How hard is it to replace that seal?

 

[rockola1971]

Okay so I have to replace the rear transmission seal then. It's leaking. Does the adapter for the Transfer Case have to come off the transmission? I can't find any YouTube videos or any written directions on my 1st look around on the old InterWeb. Is there one seal, or more? I need pictures! LOL! More work I guess. How hard is it to replace that seal?

Your tranny is likely a 4L60E but this 4L80E video will do.