I have evo 9 MR with 50,000 miles on it. Did the routine trans / T-Case / rear Dif oil change and about week later I notice that transmission oil is leaking into my transfer case and coming out of the transfer case breather hole on top. I checked the transmission oil and it was low and pulled the filler plug on the transfer case and oil was coming out. I drove about 200 miles before I discover the issue and haven't heard the notorious death whine or anything noises coming from the trans / t - case, so I hope I got to the problem in time.

I'm in the process of changing the seals and o - ring in the transfer case that mates with the transmission, hoping that will fix the problem. Has anyone encountered this problem before and what was the issue and the solution? I've been told by shep transmission that it could be internal seals in the transfer case, hoping its not the case . I also have no idea how this happened as well. The only thing I could think of is that I overfilled the oil. Though I filled it correctly but everyone makes mistakes.

 

Replacing the o-rings will probably fix your issue. There's a small one at the top of the tcase, i'd bet that's your culprit. The link below shows what i'm talking about.


https://www.evolutionm.net/forums/ev...ll-o-ring.html

 

Maybe the transmission breather is plugged and the transmission is pressurizing.

 

Did you ever figure out this issue? I think I am having the same problem 😩

 

Doesn't the trans (gearbox) oil service the front diff that is located in the transfer case?