Oil Leak Help

Hi Everyone,

I know this might be dumb question but trying to figure out what's going on with this, i was working on truck and noticed oil covered tubes, and just those two you see in the image, this is top view of driver side, with arrows pointing to help with orientation. Anyone know what for these breathers are, I know there is one behind engine for transfer case, but didnt know what these two would be for one is probably for front diff i would assume but what is the other for. Oil stain doesn't smell like diff oil for some reason ether, typically that stinks bad any advice or things to check out would be greatly appreciated. I checked all over don't see any other leaks that i can find.

 

Those are for the front diff and front diff ADD tube.

 

What you mean ADD? isnt oil added to front diff with plug on buttom?

 

Yes, oil is added to the diff through the fill plug and drained through the drain plug but a tube is bolted to the right side of the diff that reaches over to the passenger side CV axle. There is a small electric motor on that tube that actuated a fork and collar to disengage and engage the front passenger axle (for 4wd). That tube housing has a breather on it. So does the pumpkin. Those two are why there are two hoses.

 

Gotcha, any idea why i would see this much oil on it? kinda curious.

 

Not sure, for some reason I guess it’s making its way up the breather, but I don’t really know why. I’ve seen this before but never seen anyone figure out why. However, if it doesn’t smell like gear oil then it might be something else that just landed on the hoses/breathers.

 

yea its very odd, as everything around is super clean and just those two hoses are covered in gunk. Anyone know if amsoil diff smells bad or not, RSG guys did oil replacement in all diffs/transfer/transmission and wonder if its that maybe just amsoil doesnt stick as bad as typical diff oil does. who know gona wash bay and see if anything pops again.

 

One of the breathers might just be clogged, causing pressure to build up and fluid to come out (and get on both of them).

 

If over filled, the front differential can push gear oil out the vent.
As can using a different weight fluid. I’ve seen it happen.

 

I can understand that on overfilling, but I don’t get it for higher viscosity. If higher viscosity can cause it, then why doesn’t it happen on all that run higher viscosity? Just thinking out loud.

I’ve had 85W-140 conventional from Torco in mine for 23K miles with absolutely no issues.

 

These vent tubes help the front diff breathe and maintain equal pressure with the outside. This prevents seal failure from pressure differences.

Now there is another effect that they do, and that is they breath. When the vehicle is run and heats up, air moves out of the diff, when it cools down air moves back into the diff. This breathing can and will draw moisture into the diff. This moisture will get boiled off on the next heat cycle. As it leaves it will cling to the vent and allow the road grime to collect on the vent tubing where it exhausts. That is some of the gunk you see.

The other effect of the breathing is the oil can be moved up and down the tube if it is splashed up into the tube opening inside the diff. Some will make its way to the vent opening as well. It is very small amounts. Nothing to be concerned about.

 

I don’t know the answer to that.
But the majority of people who had theirs leak from the vent were using heavier weight, including myself.

 

thanks guys, gona check it out. i would assume its not showstopper, or something of grave concern at the moment.

 

Amsoil diff fluid DOES SMELL BAD.