I thought my diff is making little bit louder whine today.
So I checked my diff and found out there was(is) little leak.
It is only on the driver's side(no front, no passenger) and the leaking was not from the oil filling plug.
So I wiped the leaked oil and drove for 10 minutes but there was no more leaking and sound seemed normal.
The last time I changed my oil was 1 year ago and no leaking was there then.
What can it be? Is it Broken axle seal or what can be the reason for it?

 

Looks like a leaking seal. Part is under $20 and the job is about an hour.

 

Looks like axle seal

 

Thanks guys!

But can it be leaking from vent?
Does leaking from vent shows different pattern of leaking?

 

Looks like it is cracked to me.

 

The vent is on that side. Clean it all off with some brake cleaner, run the car a few miles and take anothe look. If nothing then the vent blew some out. Happened to mine after driving hard for a little while.

OR, you can reach up by the vent, use a mirror to see (however you want to do it) and check for fluid by the vent.

 

I always garage my car and I did not see any oil on my floor.
Does it mean it can be vent or just little leak from seal?
If whole case is cracked, wouldnt it leak a lot more than this?

 

Your pics are not so good, but it looks to me like you have some hairline cracks.

 

The red painted area was covered with oil+dirt(from just looking from bottom)


This is taken from the front driver side


This is taken from back driver side


It is taken from the top


Also from the top


It is from the top toward mid-plane

Also drove for 10 miniutes but no further leaking or any noticeable sound from the diff

 

I looked at the diff but was not able to see hair line cracks. Can u tell me what area you think it might have to crack please?

 

[Update]
I just opened filling plug to add more diff oil to compensate leaking.
But diff oil came out from the filling hole as soon as I opened the plug.
Does it mean there is no significant leaking?(Or no seal and crack)

 

i saw those too.



right of the circle.

 

The "hairlines" I thought I saw may have been manifestations due to the bad pics.

If you can't spot any, I suggest you get a magnifying glass and look all around the wet area seams and joints.

 

The vent is leaking, you can see it all wet in the pic third down from the bagged and tagged carrier. Very common problem, even in the V6 cars. GM has you relocate the vent by using a hose and another vent rattler, but all it does is move the leak. The next fix is to take out the diff and remove the fluid deflector inside the carrier. The newer ones didn't have the deflector and you didn't say what year you had, so it may not be a concern. I can't remember what year they dropped the deflector anyway. '07 I think. You can try keeping the fluid 1/4" inch below the fill hole, but don't go any lower.

 

I would say you're just fine. When liquids get hot, they expand, and then blow out that hole.

I wouldn't worry about it.

But definitely in a month, put it up on stands again, and take another peek at it just to make sure.

-meaty

 

It's the vent. The dude above knows his ****. Mine was exactly like yours (same exact leak pattern) and when i installed the diff bushing i just popped the cap off the vent, put a foot of clear tubing with a hose clamp on the vent and ran it up as high as possible. If it still pukes fluid mount a small breather can. You said when you removed the fill plug fluid poured out so it was over full adding to the problem ( or causing it) so get the level correct and you probley be ok.

 

Mine was wet like this the day I got it and I was in panic mode as well. I kept it for 2 years and put 80k on it and never had a problem. I had it checked twice and both places told me it was the vent as well. If it's not the seal then just roll with it.