Update: I replaced the seals and have the transfer case back up in the truck. My assistant and I had a surprisingly easy time getting it back up in place and getting it lined up with the transmission output shaft. Before reconnecting all the vacuum lines I flushed them all out with some Simple Green and compressed air. A bit of ATF came out of the lines with that treatment.

I also took the actuator out from under the battery. I got about a half cup of ATF out of that. It's not ruptured and it seems to hold vacuum but I'm going to replace it anyway. It seems like a good idea to replace it. The ATF can't be good for the rubber diaphragm.

I expect to get the new actuator in the morning and put everything back together. I've got the underside of the truck put back together except for the two drive shafts. Hopefully by the end of the day I'll have it ready to drive out of the shop.

I forgot to put RTV on the mating surfaces of the transmission and transfer case. Is that a problem or should I not worry about it?

 

It seems to me, if I remember correctly, there is an O ring between the transmission and the adapter, and either a gasket or RTV between the adapter and the transfer case. Hopefully someone will correct me if I'm wrong.

 

Normally there is a gasket between the adapter and the transfer case. When we removed the transfer case the gasket came apart. We scraped the old gasket off the transfer case and cleaned up both mating surfaces but it went so smoothly getting the transfer case up under the truck that we completely forgot to use any RTV to seal the adapter to the transfer case. I'm just hoping there won't be a major fluid leak where they go together.

I'm also really glad that I replaced the rear seal on the transfer case. The new one seals up very well; much better than the old one.

 

With no gasket or RTV, you'll probably be back in there again.

 

That's not the answer I wanted. What I wanted to hear was something like "Those Blazers never leak *ANYTHING* from underneath."

I am curious, however, to see how long it takes for ATF to start leaking from the junction of the transmission adapter and the transfer case. I hope, at least, it waits until warmer weather to start leaking. I'd rather pull the transfer case again in warmer weather.

It's all back together and the HVAC controls are working perfectly. Thanks for all the help!

 

dont worry they never leak there.

 

UPDATE: Cap'n, you were right as rain. I'm working on the Jimmy again and I found it dripping ATF from the joint between the back of the transmission and the transfer case. Looks like I'll be taking it apart again after I finish all the front-end work I'm doing.

Should I use RTV silicone or try and find a gasket?

 

Ugh, bad news that you need to do it again It got you by for a while though. Monsoon season is on its way to you, but that's better than doing it in a snow bank DO NOT use RTV, use the gasket, go to the dealer to get one if you have to.

 

I've been disappointed in winter this year in the Northwest. I bought insulated coveralls last year and I only got to use them for a couple weeks this year. We haven't even had enough rain to qualify for a real Northwest winter. I have an accordion student who lives in the Cascade foothills and I've only ever needed 4WD to get to his house ONCE this year.

At least with the job of putting a new gasket on this one and replacing the seals on my '93 I'm getting good at removing transfer cases.

 

I just had another thought: it would save me some time on the job if I could just cut the top of the gasket and slip it past the input shaft without completely removing the transfer case from the back of the transmission. Would that be a bad idea? If the cut in the gasket is at the top the fluid shouldn't leak out of it.

Normally I wouldn't take such a risk but my helper is now an actual professional mechanic working six days a week so I have to do this job myself. If I don't have to completely remove the transfer case there's less chance of me dropping it on the concrete floor and breaking it.