cor66vette

Tried this in the Tech section with no responses.

Once after a 750 mile drive, I noticed this leak. I wiped it down, got it all nicey nicey, and it's seemed to be fine ever since. That was September 2012. BTW- I do check it often especially since this leak was first noticed right after I bought the car and drove it home.
Recently, I took a trip and put on about the same mileage, and here the leak is again. Seemed to happen only after these two sustained drives. No prob after regular drives.

It smells like gear oil, but I don't have the best sense of smell.

It's an '03 50th AE 6-speed Coupe with a little less than 7k miles on it.

Any thoughts on what is causing the leak and what my next step should be?

I took some pics- hope they make sense. Thanks

phoneman91

I would suspect that the differential vent is the source of the leakage. If I understand correctly-it only occurs on long drives.

I would suspect that the differential fluid is expanding because of the added heat of the long drive and overflowing from the vent. This would explain why normal length drives aren't an issue. Short drives don't heat the fluid enough and doesn't cause enough heat expansion to overflow the vent.

Check the vent and see if it is wet. And as always with a leak-the highest part that is wet is the source of the leakage.

If the leakage is from the vent-I would suggest draining the oil and making sure that it is refilled at the correct level.

HawnHog

I had a similar leak. Took it to my friendly transmission shop with a big repair bill in mind. I was told it was the vent tube. Said it was a common issue. He relocated the outlet to a higher position and 8 months later no leak.

cor66vette

I see you edited and added this portion to your initial reply and I see why- because it's important! Is there a better than other fluid to use? Thanks

cor66vette

I'm getting under the car again tomorrow to try to determine the origin of the leak. I'm hoping it's a simple matter of the overflow, vs. another problem. Is relocating the vent tube a big-to-do? Thanks

phoneman91

I am just a three month C5 owner--but it shouldn't be difficult. The vent will be at the top of the housing and may have a hose connected to it and the other end of the hose not connected to anything-but routed higher than the vent assembly.

phoneman91

Take a look at this thread:

http://forums.corvetteforum.com/c5-t...d-removal.html

And here is a picture of the top of the differential assembly with the vent assembly shown on the driver's top :

http://www.digitalcorvettes.com/foru...ad.php?t=41610

I noticed that the driver's side of the differential seems to be more wet and if the vent is on the driver's side of the differential assembly-this would make sense.

megawatt1203

Update: This was written in 07/12. Still dry even after running hard. Just completed this fix on my 2000 Vert. Had the left seal and o-ring replaced a couple years ago when I had my S/C installed. Still had occasional leakage. No apparent leakage all winter long. Made some long spirited runs this summer in hot weather and leakage returned. Level is OK now, might of been filled to drain after fix 2 years ago. Used 2' piece of 3/8" ID and clamped it to old vent with cap, spring and rubber removed. Double looped the hose and cable tied it to brake line. No vent on end of hose, placed screen over it. Will see if this helps!

Mark

cor66vette

Thanks. So the idea is to make the vent tube longer -aka higher than the rear?

cor66vette

Yeah, you're correct. It is ONLY wet on the driver side. Thanks.

cor66vette

Thanks for that. Am I safe to assume that you lengthened the vent tube and raised it higher than the dif?

megawatt1203

Didn't lengthen the existing fitting, removed the vent cap and clamped the hose to the existing fitting. If you haven't yet, check out that thread in post #7, there is a great picture of the vent. The base of the vent remains in the diff.

And yes, the idea was to raise the vent slightly higher than the OEM vent. So far so good for me...