leak btwn transfer case and transmission

Vehicle: 89 S10 Blazer, 4X4, NP231C, 700R4, 4.3L V6

There is a bad leak of ATF between the transfer case and the transmission, where the factory tailhousing adapter meets the transfer case. Both units use ATF.

Now, I thought the 231 was sealed front and rear-Thought the 700R4 was, as well?

Transmission is a fresh rebuild, literally by the best guy in town . I am told that there is no seal on the rear of the 700R4 in this application, as it normally in a 2WD configuration is sealed by the slip yoke and the seal at the rear of the tailshaft housing, and in a 4WD application by the presence of the adapter housing and all the associated orings and so on between transmission/adapter/transfer.

Transfer could probably use a looking-through, but I'm not going inside her till I have a SYE kit to install.

Thoughts? I'd like to think it's as simple as my not having had the proper oring when I assembled them all, and having used RTV and not made the proper seal between trans and adapter. Still, that's a lot of work to tear it down and find out it's not the solution.

BTW- transmission is losing fluid, though I'm not convinced it's not from a leaking cooler fitting

Reply to
nyb
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Sorry- it's me, burntkat. Was futzing with someone in another group and didn't change it back...

Reply to
burntkat

There is a paper gasket between the tranny and the t-case. These are prone to leaking (ask me how I know). Easy enough to pull the t-case and replace the gasket. I actually just slid my transfer case back a few inches, cleaned up the mating surfaces and used liquid gasket. A good year later and Jimmy ('91 T-15, 4.3L. 700R4) hasn't lost another drop of ATF.

The only seal between the t-case and the tranny is actually on the t-case side while the tranny side is wide open with the t-case out.

Unless I'm mistaken about the model numbers the transfer case should be filled with gear oil, not ATF. If you find ATF in the transfer case then your seal is gone as well (another common occurance) and the transfer case will have to be dropped altogether to replace it (been there, had it done when I was to new to do it myself, remade the gasket a couple of years later).

Reply to
SBlackfoot

Thanks SB. I believe you're right about the 231 taking gear oil now I think about it. Good to hear that I was on the right track with the tcase, too. Now I think about it, I've noticed that the 700R4 I took out of the Blazer last year was leaking oil out of the tailshaft like a mofo when I moved it over here. There is a paper gasket between the tranny and the t-case. These are prone

Reply to
burntkat

. . ===== =====

snipped-for-privacy@nowhere.com (nyb) writes in.......

hope Doc reads this one Vehicle: 89 S10 Blazer, 4X4, NP231C, 700R4, 4.3L V6

There is a bad leak of ATF between the transfer case and the transmission, where the factory tailhousing adapter meets the transfer case. Both units use ATF.

Now, I thought the 231 was sealed front and rear-Thought the 700R4 was, as well? Transmission is a fresh rebuild,

literally by the best guy in town,

all the Corvette and custom truck guys use him, he knos his stuff and comes highly recommended from several folks. I am told that there is no seal on the rear of the 700R4 in this application, as it normally in a 2WD configuration is sealed by the slip yoke and the seal at the rear of the tailshaft housing, and in a 4WD application by the presence of the adapter housing and all the associated orings and so on between transmission/adapter/transfer. Transfer could probably use a looking-through, but I'm not going inside her till I have a SYE kit to install.

Thoughts?

I'd like to think it's as simple as my not having had the proper oring when I assembled them all, and having used RTV and not made the proper seal between trans and adapter. Still, that's a lot of work to tear it down and find out it's not the solution.

BTW- transmission is losing fluid, though I'm not convinced it's not from a leaking cooler fitting

Reply to
Marsh Monster

The end of the transmission is open to the transfer case adapter. The 231 transfer case takes ATF If you are losing trans fluid and it's not leaking on the ground then replace the input seal of the transfer case. I recommend you buy the new seal from the dealer, because it will be a special made double lip seal, if you buy a National or a CR seal it will only be a single lip and you would need to install two to match the OEM seal. There is a gasket between the transfer case and the adapter and a square o-ring seal between the transmission and the adapter.

Reply to
WBucha

Now, Marsh- if you're done making assumptions:

he did in fact suggest all this. I didn't replace the seals on the transfer, because I wasn't concerned abot the transfer leaking externally, as it hadn't before and I wasn't about to tear into any part of it until I actually get the SYE kit- as I mentioned before. When I do receive that kit and get to that point in this project, I'll do a full rebuild of it. Till then, I'm not about to disturb anything on it.

Not only did he mention the adapter gaskets and orings-- he gave them to me. However, in the intervening 3 months between receiving the parts back from him and getting enough time in town from work to install them, I misplaced them-- so decided I'd just use RTV. Knowing full well it might leak. Sometimes you have to take a chance.

He is indeed the best trans guy in town, whether or not you want to believe it. Matters not to me.

Reply to
burntkat

Wow could that have been any tougher to read?

Reply to
SBlackfoot

Are you sure about that? I'm fairly sure the stock t-case on my '91 is full of gear oil rather than ATF (offhand I think it's grey). It hasn't been touched since a tranny shop replaced the seal on the front of the t-case a while back (long story). Assuming it's the same case as BK's '89 of course, I don't know what model number came in which years.

Reply to
SBlackfoot

If I were you, I'd pull the t/case back out and use the "correct" paper gasket. Do not use RTV in this location. And the 231 (and all of the aluminum/magnesium t/cases) use ATF, not gear oil. Unless it's an "auto" t/case, then it uses the blue "autotrac" fluid, but this won't apply to your vehicle.

Ian

Reply to
shiden_Kai

:nods: Ian. I totally agree. I tried to "get by" with the RTV and this is where I am now-- pissin' fluid. I'll go to the dealer Monday morning and hope to get it installed within the week. Still got a bunch of stuff in the garage taking up space from the move.

Thanks to all who replied-- I'm much less concerned about the leak now.

Reply to
burntkat

Yup. It could be in chinese...

~KJ/TLGM

Reply to
KJ

/. mode:

"My mother is Chinese, you insensitive clod!!"

Reply to
burntkat

I'm sorry... sucks to be you.

~KJ/TLGM

message

Reply to
KJ

nah- Slashdot is what sucks.

Reply to
burntkat

(TOP POST)

So....he gave you the O-ring and the gasket but you lost it. Then.....you decided to use silicone instead. AFTER... "the best guy in town" gave you a gasket and o-ring.

Then....you came in here and asked for THOUGHTS on the situation.

(hold on a sec.....I'm gonna run back and read yer OP again.....I'll be back in jest a sec....don't go nowhere now)

Yep.....that's what you said.....THOUGHTS.

Then...... I gave you some thought....some very good thought, I thought. But your thought seems to be that my thought wasn't quite the thought that you thought you ought to have got. Which left my post for naught. Well....you got what you got and if'n that's not what you thought you should have got.........

i'm sorry, i appologize, please forgive me, be my friend,

but first......... One last question....if I may?

Didn't "the best guy in town" find the leak when you carried the truck to him?

oh yeah...and another thought, I've sealed over 1000 transfer cases and never had a problem one with silicone.

okay....i lied....two thoughts.... You use'n that blue silicone crap ..... ain't yuh?? The kind you get down at the ole AutoZonedOut store?? You'de be better off using drywall putty. (there i go...ass u me' ing again)

Respectfully submitted for clarification of assumptions taken from original post,

MarshMonster ~no leeeks....no dreeps.....no err-ors~

========== ========== Re: leak btwn transfer case and "literally the best guy in town"(LONG) Group: alt.autos.4x4.chevy-trucks Date: Sun,

Jun 13, 2004, 3:34pm (CDT+5) From: snipped-for-privacy@nowhere.com (burntkat)

Now, Marsh- if you're done making assumptions: he did in fact suggest all this. I didn't replace the seals on the transfer, because I wasn't concerned abot the transfer leaking externally, as it hadn't before and I wasn't about to tear into any part of it until I actually get the SYE kit- as I mentioned before. When I do receive that kit and get to that point in this project, I'll do a full rebuild of it. Till then, I'm not about to disturb anything on it.

Not only did he mention the adapter gaskets and orings-- he gave them to me. However, in the intervening 3 months between receiving the parts back from him and getting enough time in town from work to install them, I misplaced them-- so decided I'd just use RTV. Knowing full well it might leak. Sometimes you have to take a chance.

He is indeed the best trans guy in town, whether or not you want to believe it. Matters not to me.

(one more thought....the best tranny guy in this town....wouldn't let his unit run all over town puking fluid out while you told everybody who built it) =========== ===========

Reply to
Marsh Monster

My problem isn't with your offering your thoughts. My problem is with the way you present yourself- like some sort of Shakespearian monologue- 10 paragraphs where one sentence will do. Going to lengths to explain something is one thing. Going to lengths to try to be funny- and failing- is another. Quite tiresome as well.

Also, this whole business about second-guessing someone when they say they went to the best guy in town for something is ridiculous- you don't know him. I only specified that because I actually DID go to the best tranny guy in town, and I've been in this group long enough to know that some tool would have to challenge it. Sure enough, I was right.

I didn't take the transmission to him because the leak isn't his fault. I did the installation, not him. I'd already come to the conclusion that there was not a rear seal pretty much, just came here to check the veracity of that. I was checking my own reasoning and if I'd found there was indeed a rear seal, I'd have talked to him about taking a look at it. I'd tried to get in touch with him several times and had no success- his business is booming at present. Something about folks wanting a really good transmission man, or some such.

Try less to be a comedian, and more to share your knowledge. I've seen your posts and know you're VERY bright when it comes to vehicles. Now you just need to realize you're not Charles Dickens. We all have our talents, and I have to be honest with you that writing comedy isn't your strong suite. town" gave you a gasket and o-ring.

Reply to
burntkat

I never found any interest in their threads even though I was/am a geek.

~KJ/TLGM

Reply to
KJ

Thank god... I thought I was the only one.

Reply to
SBlackfoot

Well for the record, and I hope Marshy reads and understands this- I was NOT attacking him. Just expressing and clarifying what the issue was.

Marsh seems to be a sharp fellow- but it gets lost when he's trying to reinvent the "Who's on first" routine... ;)

Reply to
burntkat

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