froggy47

I am having a small diff leak & when I go under to torque the diff bolts I want to reach up & "check" the vent.

Can that be done? Can anyone post a pic of a diff vent so I know what to feel for?

How does the vent work?

Should I shoot it with some brake cleaner?

When I do diff service I have never felt any pressure when I open it up.

Thanks.

froggy47

GO_BLUE_VETTES

http://www.flickr.com/photos/4706921...7623192151889/



Vent is located above the drivers side half shaft. You can see it in this photo, it is the somewhat shiny piece that looks like a thimble. You can press is like a button.

If your diff was overfilled and you got it hot, it probably burped so it'll be oily dirty up there.

Allthrottleandsomebottle

froggy47

Thanks guys. I think I'm leaking from the bottom mating of the two cases. Damned if I will disassemble the whole rear drive train for this leak.

Sucks that GM can't leak proof this.

drivinhard

if you are leaking from a mating joint, you can RTV the outside of the case for a temp fix, it will stop the leak. works until you have everything torn apart for a proper fix.

froggy47

May try that too.

Z11409

The correct fix is new side plates and gaskets.

Han Solo

I would not spray brake clean on the vent. It will most likely have a rubber disc with a spring on top to seal dirt out. Brake clean might melt the rubber to the sealing surface and make things worse.

When I serviced my diff I screwed a hose barb with I think a 3/4 pipe thread just enough to blow into the diff with a hose. Don't try to tighten it cause it is a different thread. I put a piece of hose on and blew into it until the vent opened. This was just to make sure it would open under pressure.

The one on my Mustang was stuck and pushing oil out the axle seals. I popped the cap off of it and cleaned and oiled the rubber disc then put it back on and re crimped it. Hasn't leaked since.

imp zog

I popped the metal cap off and clamped a 3/8" hose on it and mounted a breather to the end of it behind one of the tail lights. Lets it breath adequately, and the height difference helps prevent fluid splashed up there from going all over in the event of aggressive use.

That said, the cause of my leak was worn clutch plates for the locking diff (worn out from 8 years on the track). They were slipping, which generated heat, and that caused the fluid to boil and force its way out of the seal (on the left side, just under the breather cap), which made me suspect the breather in the first place.

froggy47

Side plates are dry as a old bone.