: diff vent tube



boomys10
07-19-13, 02:58 PM
where the hell is it? my diff had pressue built up in it and I need to check the tube, cant find it though lol. thanks yall!

CMNTMXR57
07-22-13, 11:19 AM
On top of the housing, towards the drivers side. Mine burps out fluid occasionally, which is the sign of a partially clogged vent.

hiltonny
07-22-13, 12:28 PM
How did you determine that it had pressure built up in it?

boomys10
07-22-13, 12:34 PM
removed the plug to check and see if the diff fluid was low and it wooshed out air. lol

CMNTMXR57
07-22-13, 12:39 PM
Because in the years I owned it, I never had issues, then one day, I get home, pull in the driveway, come out 15 minutes later to wipe down my wheels, and get the fine acrid odor of gear fluid, only to look down and see a puddle on the ground under the diff. Went inside, logged into GM SI, read up on the vent specific to our cars (most are just tubes, ours has an actual valve in it), and it said if you get fluid, it's backed up and enough pressure was built up inside, to blow it out finally. which is indicative of a partially clogged/fully clogged vent.

That would actually make since as before I got home, I had a drag race with something and I hammered the car hard out of the hole.

hiltonny
07-22-13, 03:59 PM
If the design is the same as Corvettes; the one way vent allows air to escape when the fluid gets hot and expands, when the fluid cools air cannot re-enter and a vacuum is created in the differential to reduce any leakage through the seals. If the fluid gets hotter from racing then some fluid can escape out the vent where ever it is but this is normal. If the air you heard was going into the differential not out, then there is a check valve vent and it's working ok.

CMNTMXR57
07-22-13, 04:36 PM
The issue wasn't that it vented. The issue was that it more or less built up enough pressure and exploded out the vent and I had a large puddle of some Royal Purple under the car. Not just a few drops. At first I thought I had of course broken something. I then tracked it back up to the differential housing, then followed the yellow brick road of gear fluid up the diff housing from the path it took down (the back drivers side of the housing). It's been fine ever since, until the other night when I smelled it again, and sure enough, a small drip had come down. So next oil change, when I have it up on the lift, I will take it out and clean it.

Which per GM, is a partially clogged/clogged vent as it wasn't functioning normally.

hiltonny
07-23-13, 09:42 AM
The shop manual shows the vent on the drivers' side behind and above the left drive axle, it states that the vent can be replaced if there is excess leakage. I was surprised to see an external oil cooler shown that includes an electric pump and what looks like a fan.

boomys10
07-23-13, 10:32 AM
oil cooler for the diff?

CMNTMXR57
07-23-13, 10:42 AM
Yea, we didn't get it. First thing I saw when I looked it up in SI and asked why we didn't!