Transfer case oil leak

So, I noticed about a year ago, oil residue on the bottom of the T case and collected in my transfer case skid plate.

to me it looked like it was leaking from the fill plug. I took it to the dealer.

brought it to concord Toyota in CA. They did nothing but pressure wash the area and install dye into the T case and told me to come back after 5,000 mi.

Well it's all oiley again and 5,000mi later and brought it in Again. The tech called me and says the dye indicates it's leaking from the fill plug and he put a new fill plug gasket and torqued it down.

my question is. What could cause it to keep leaking here? This will be third time the gasket has been replaced and the plug torqued. Once by myself.

Anything else I should be looking into? The 6 year 60,000mi warranty is up in July. So I've been trying to get this addressed for over a year now.

here's some pics of the skid plate and can see the dye collected there.

 

Do you know for sure the fill plug is the source of the leak? I would hope your dealer is not jerking you around until your Powertrain warranty expires.

 

There's probably still dye in there, unless they changed the oil (they'd charge extra for that). So if it keeps leaking you can figure it out.

Is there a scratch on the surface where the gasket seats?

It would be worth checking the breather. If it's clogged it could build up pressure or vacuum as the temperature changes.

 

No I really doubt it is, but the dealer seems to think that is the source. The gasket/washer has been replaced and re torqued twice before this last leak. Once by myselft and once by the same Dealer. the Dealer wants to try it again tho...

 

I did mention the breather to the tech and he failed to check it. He stated that if the breather were to fail, we would see dye/oil up on the breather hose leaking way up high from the hose. He had me follow the hose up to the breather up and kept saying we would see dye up on the hose itself up near the firewall. It didn't make any sense to me honestly what he was trying to explain.

 

Likely the seal between the tcase and transmission, seen a few.

Do you have photos of the actual leak?

 

I do not. The only traces of dye I could visually see were at the very bottom gasket where the two halves mate. And near the front propeller shaft seal. Everything else was clean. The tech says he saw a trail coming down from the fill plug. But I did not see that. Gonna drive it this week and try and inspect it each day with the UV glasses and light. I'll try to get some pics of what I find. I'm guessing I'll need to drive around in 4wd to get it to leak if it is coming from the front propeller shaft?

on another note. Do you think if they keep running me along with this issue until I'm out of warranty in July I could get them to continue to cover it if it continues to leak after, since they just keep failing to diagnose the problem and just keep cleaning/re checking. And torquing the fill plug...?

 

did they ever take a look at transmission oil level? Did they ever show it on paperwork is needing fluid serviced?

 

not the tranny atf. No leaks up near there and dye test indicates it for sure came from the T case.

 

my thoughts were there is a seal that keeps it trans fluid from mixing into the transfer case. Transmission is a higher pressure than a transfer case could leak into the transfer case raising the fluid level causing leak from the fill plug.

 

If that was the case the fill plug would not leak...it has a gasket. When the tech checked it and removed the plug to put a new gasket on it, the excess would pour out. He didn't mention that happening.

 

There are two seals, one sealing the tcase input to the rear of the transmission, and another seal on the front of the transfer case sealing the transfer case input to the transfer case. Typically, if a leak occurs at either seal, fluid drips down and out of the transfer case to transmission mate surface. It would be pretty hard for fluid to leak out of one seal and bust through the other one….its going to drip down.

It doesn’t matter, but also as mentioned above, if the t-case did end up gaining fluid, the fill plug wouldn’t leak, since it has a gasket on it. It would just gain more fluid and eventually maybe push it out of the vent.

It’s not relevant to this thread but the manual transmission could potentially gain fluid from the transfer case. The transfer case seals to transfer case input, and the transmission rear housing seals via an o ring to the transfer case housing. So technically, the front side of the t-case oil seal is exposed to manual transmission fluid. So if that seal went bad, there’s a chance fluid could interchange between the two. For fluid to actually leak at the mating surface, it would have to get past the o-ring.

Rear of transmission:


Front of transfer case

 

Ok……thanks for the education fellas.

 

So update. It's been almost 4 month and the leak has returned. It's leaking where the transfer case mates with the transmission I can clearly see it now with the UV Dye and Glasses. I will make an appointment and bring it back to the Dealer for a third time. Problem is, now I'm out of warranty it expired in July. So hoping they do the right thing since they have been just stringing me along for over a year to do any work to the vehicle. My thoughts are that it's one of the two seals that BLtheP is referring to above.

 

Any updates on if they finally fixed it and if they made you pay?

 

not yet. I have not had time to bring it in to the dealer. I won't have them fix it if they deny it under warranty. I will most likely try and take it to corporate if so. And fix it myself.

will keep this thread updated.

 

Made an appointment tomorrow with Concord Toyota in California. not holding my breath but will update as soon as I hear what they say. Curious what excuse or quick fix they will come up with this time to get out of doing any work to it. what's interesting is that there appears to definitely be some yellow dye color at the Tcase gasket the gasket where the two halves of the T case mate. but there is yellow air bubbles coming from the gasket where the transfer case mates to the transmission I've attached a link to a video here where you can see the yellow on both area's i'm referring to. This video was recorded after my drive home which is about a 10 minute 7 mile drive from work to the house.

https://www.youtube.com/watch?v=sFbuzJ6DlNU

 

Just got off the phone with Concord Toyota, They guy on the phone stated there are three separate seals that all need to be replaced and he needs to order them. That one seal they have to call toyota because they don't have a part number for it. He started to get into pricing and I stopped him and stated no this should be all covered under warranty. He asked if I had an extended warranty. I explained to him just as I explained to him the first time I spoke with him that I was expecting this to fully be covered under the 60mo 60,000mi warranty. That I took the truck in twice previously for this same issue while the truck was still under warranty and the repairs have not been successful, or even attempted. He said he will speak with his manager to try and get it covered under warranty, but not making any promises. We will see what happens at our next conversation. I will likely start looking for an attorney. Sad what this has come to. What good is a warranty if they wont perform any repairs until you are out of the warranty?

 

So I just went back down to Concord Toyota. The Gentleman at the service desk informed me of the good news that they were not charging me for diagnostics of the problem. but bad news $3,000+ worth of seals that need to be replaced and would not be covered under warranty. I almost lost it in the service desk area but calmly walked outside. Got on the phone with Toyota customer care 1800 331 4331 number explained to them whats going on. They called this gentleman back and we spoke some more on the phone. he's gonna see what his manager could do. seems very strange this whole thing that this is how they handle business. Why wasn't this problem fixed on 1 or 2 of the previous visits last visit they diagnose a .10 cent crush washer as the fix and this visit $3,000 worth of seals to be replaced? This makes no sense. he's saying the reason my warranty Is denied is because the invoice from my last visit states to bring the truck back in 1 to 2 weeks. however on my invoice it does not say that. it just says "53888 Inspected with black light. Dye seen around the fill plug. Replaced fill plug @ torque to 27ft lbs cleaned oil as needed. No further action required." So they attempted to fix and it's still leaking, the way I see it their fix wasn't sufficient.

 

having a hard time locating the part number for the Transfer case input shaft seal located in that picture above the brown seal. been searching for hours. is it 90311-51009?