Hey guys,

I have a 05 EVO 8. Anyways recently I noticed when i put the car up on the lift on the rear diff there is a leak coming from the top...it's not from where the gasket is but almost like its coming from the top of where the axles go into the diff. However I don't believe this to be the case based on my observation. I checked the level of the diff fluid and it is right where it should be... So I guess what I'm asking is there a vent that fluid will come from if it's over filled? Because shortly before I bought the car it was serviced at the dealership and I'm wondering if they over filled it. Any help would be much appreciated.

 

yes id agree with the overfill theres a vent in the top of the cover

 

There is a vent on each of the gear boxes, transmission, transfer case and rear differential. The vents allow air pressure created when the gear boxes are hot to escape. Otherwise, the air pressure might force lubricant out through seals.

Vents shouldn't leak lubricant. If the vent is the source it might be reason for replacement.

 

Ok well the leak seams to be coming from the top so what else could it be coming from? Are you positive the vent doesn't act as a safeguard to overfill? And could overfill cause so much pressure that pushes it out the seals?

 

Well, you say you just had it serviced so maybe they squirted oil all over it. My wife's car, when we were first married, made a puddle of oil on our garage floor. Three months later it stopped dripping. The answer - the place where she was having it serviced put some oil in the engine and some on the engine and this was at a dealership. Get a can of degreaser spray, clean the case and see of the leak reappears.

BTW, you also say the differential is not overfull.

 

Well usually when I wiped it off it would come back. However right before I left for Florida two weeks ago I cleaned it off real good took it to summit racing about a 40 min round trip drive came home and didn't see any leaking but then I left shortly after so I come home tomorrow and I'm gonna see if it's leaking again so I'm crossing my fingers!! Hoping now the level of oil is correct and before it was just overfilled. It's just funny cuz a stream runs down from the top and is identical on both sides which is weird to me...

 

The vent, as I remember, is on the rear cover at the top, if that is any help. These vents are rubber and are installed with sealer. I knocked the one on the transfer case hard enough to break the seal and then it started leaking. I wasn't sure what was happening so I bought a new vent and installed it with RTV. No more leak.

 

The only thing I can feel at the top is a rubber nipple that feels like a moveable valve that pops up and down does that sound correct?

 

I'd have to crawl under before I could answer your question. That will have to wait until tomorrow.

 

Ok I'd appreciate it.

 

Yeah, a little clicky button thing. The area around the one on my car is bone dry.

 

Yeah so is mine so I have no idea where the link is from..