Experts opinion: Transfer case/Transmission interface leak.

[roncruiser]

Differential oil is leaking or seeping out where the transmission mates up with the transfer case. In other word: where the Front Case of the Transfer Case interfaces with the Transmission.

Looking through the manual, I can't find what type of seal is used between the transfer case and transmission:

1- Is it a precut gasket?

or

2- Is it the red/orange Toyota RTV?...

... how tight should those bolts be torqued down to?

Thanks guys....

 

[RavenTai]

I have not seen this area myself but I would be surprised of the chamber between the T-case and trans is wet, I would think that chamber is dry and each shaft (transmission output and transfer input) have their own seals, if so then you need to drop the transfer and replace the input seal,

take a close look at the bottom fo the interface split between the two see if you can find a weep hole where this fluid is coming from.

 

[roncruiser]

Bummer! So that interface has no seal because it doesn't need a seal. It's something else then. As you said, it should be dry. You're thinking it might be the input seal. You're probably right because I know its diff. oil leaking. Definitely smells stinky like diff. oil. I'll look again for a weep hole.

 

[knorrena]

There is a seal on the output shaft of the tranny and one one the input shaft of the tcase. The cavity is not sealed by a sealer or gasket. At least mine was not. My guess is that you have one the two or both of the aforementioned seals leaking.

 

[roncruiser]

It's probably the transfer case input shaft oil seal, because it's definitely the smelly diff. oil leaking out on to the ground. I go low on diff. oil and occasionally have to top off the center diff, and tranny fluid is still good and doesn't lose any.

 

[roncruiser]

90% sure it's the input shaft oil seal. The weep hole at the transfer case/tranny interface clearly indicates fluid coming through the hole. Definitely, diff. oil.

 

[RavenTai]

How bad is this leak? be aware the transfer does not hold much fluid, something like just over 2 quarts, is it something you could fill once a month and keep up with?

 

[roncruiser]

RavenTai... you were absolutely correct. It was the input shaft seal. Repair covered under warranty.

 

[bjustice]

Ugh I think this is my problem as well. I just bought a 96 LX for my wife for her birthday and on the way to the movies the check oil light came on. Checked the oil and it was definitely low. Went straight home and noticed a nice sized oil spot on the driveway . Drained the remaining oil and put new in. Cleaned up the oil stains underneath and went back an hour later to check and noticed that the oil was coming out on the seal on the transmission looking thing behind the oil pan. I assumed this was the transfer case/tranny connection. It is not coming out quickly but enough to where when I clean it off, I can see it start to seep through again. There is a funny little plastic door on the front side of the unit that I can pull off (it's not on there very tight) and it appears to be dry inside. Not sure what to do, any suggestions? This doesn't seem like a cheap fix.

 

[RavenTai]

Bj, what you describe is a little different, that door is into the bell housing of the transmission, the engine can leak into that chamber two ways, the upper oil pan seal, usually called "pan arch" here, and the rear main seal, both are common leaks, the transfer case is further back at the end of the transmission,

When you are paying someone else to do the work yes that can be an expensive fix

I would watch the consumption If it is only a quart oil every few thousand miles I would ignore it an djust keep up with the oil, my rear main was leaking when I bought my 96, that was 100K miles and 5 years ago. still just a minor leak and I am not going to remove the transmission over it.

 

[bjustice]

Thanks for the info Raven. This is my first 4-wheel drive vehicle so I'm still learning what everything is. At least I can crawl under there with ease without having to jack it up . The seal that is leaking has a little weep hole at the bottom so I pretty much assumed oil should not be in there.

I crawled under a friend of mine's 92 FJ80 today and noticed it looked pretty much the same, dried black oil underneath and fresh oil on the bottom of the bell housing where the weep hole is. He does not notice any dripping so I'm thinking mine is in a little worse shape than his. I hit some train tracks the other day a little quicker than I should and I'm wondering if that jostled the engine/tranny enough to break the seals. I drove this thing home on the 16th of January about 600 miles and when I got home the oil did not seem to be any less than when I started the trip. This makes me think it was always leaking a little bit but I may have made it worse.

I am going to keep my eye on it over the next couple of weeks and monitor how much is leaking out. If it were my car I wouldn't really care but I hate to have my wife driving around in something that may be leaking a significant amount of oil.

Thanks for all the information.

 

[RavenTai]

LOL

The vehicle you are driving a quite a bit more robust than you think, perhaps getting hit by the train while driving over the tracks might cause an oil leak, Otherwise it is just normal wear of a chunk of rubber over the past one and one third decades,

 

[mrg93lc]

Here is the seep hole from my 93

 

[mrg93lc]

Here is another close up.

 

[mrg93lc]

Does anyone have a cut out drawing of the output seal location of the transmission where the weep hole is located?