Well, I suppose it had to happen. Pulled the vette out last night to go for a quick ride with the spouse. She was inside getting ready, so I fire up the leaf blower to clean out garage while vette is in driveway warming up. While cleaning out garage, I notice several oil stains directly in line with the most recent tire marks on the floor. They are slightly to the left (viewed from rear) of the center line of the car. The fluid was a clearish yellow. I assume this is diff oil? I shut the car off and crawled under and noticed some oil, but it was too hot to stay under there. When we got back last night, I wiped the drops off the floor. Just now, I pulled the car out of the garage, and there are no new drips, but I was able to get under and get a good look around. Seems to be mostly coming from the drivers side half shaft area, although there is some wetness on the pass side as well. There is a good bit of oil spread under the car. It is on the springs, boots, exhaust pipes (thought I smelled something this weekend), underbody, cross member, etc. Also, there is a fairly good bit of oil on the back of the car (GA tags are white, and right now my tag is covered with black spots where the oil has attracted dust).

Anyway, I've read a number of posts on this topic, and have some questions. Seems some folks report leakage right after delivery. This is attributed to over fill by the factory and eventually goes away. Is the diff vented or a sealed system? I've got about 8600 miles on my car, and like I said, this seems to be pretty new. Could this have been caused by extensive heat? We did a road trip from ATL to Knoxville and back last Saturday and it was around 100 degrees. Could excessive heat have pushed some fluid out? We did the trip at about 80 the whole way.

Also, the gaskets that seal the side plates to the diff seem to be a common problem (and based on where the oil is on the boots, I suspect this is the case). How involved is the gasket change? I've also heard there were problems with the aluminum in the casting itself which requires a whole new diff.

For those in the ATL area, anyone got the number for Tom Jumper? I guess it's time to schedule an appointment with David F. Will also have him address: rocking seat, deck lid allignment, hard starting, oil consumption (about .5 quart per 1000 - I know, not enough to do anything about, just want it on record.).

I was going to go on a rant about this being a 50K car and having so many problems, but lots of folks have been there, done that. Let's just say, it will take a lot of convincing to put me in another GM product when the lease is up on this one. Can you say Clown Shoe?

:mad :mad :mad

 

The breather for the diff is on top and to the left. There's a good chance that it's just over-filled. Mine was. Level the car, pull the fill plug and see what comes out.

-Blackjack :flag

 

Mine was neither overfilled, nor leaky gaskets, but the aluminum covers. My car only had about 1400 miles on it when I noticed my leaking problem. They replaced both gaskets first, but the leak continued. Turns out there was a porosity problem in aluminum cover, due to improper manufacture. Took about a day for them to replace the cover, under warranty, of course!

Best of luck to you in getting it resolved, mine took 3-4 visits to the service department before all was well with the rear end.

 

Blackjack,

Do you think that an over fill situation would only show now after 8600 miles? I've worked the car over quite hard on the canyon (well hey, it is the East Coast, we call 'em canyons) roads, and never experienced this.

BlueC5Kitten,

I had heard about the casting problems with the side plates as well. When they started with the gaskets on yours, were the gaskets between the side plates and the center chunk, or at the ends of the side plates where the half shafts come out? I would say mine is not leaking where the plates bolt up to the center chunk, but rather where the shafts come out.

Other thoughts? Thanks in adance for your replies!
:rolleyes:

 

It's possible. My over-fill didn't show itself until about 6,000 miles. It was after a hard canyon run also. It threw oil all over the place. You won't know until you level the car and pull the fill plug at the top of the diff. You can also feel around the breather tube to check for gear oil residue.

-Blackjack :flag

 

Blackjack,

Thanks again for your insight. Very well could be overfill being pushed out by a long run in the heat wave we're having here. Can you give me more direction to the fill plug (location - front, rear, left, right - obviously on top), and style of fill plug (allen, hex, square, etc). I'll go out and look in a minute. I assume if it's over full, fluid is going to pour out and if low, won't see any at the threads? This could be good news! You people are GREAT! :yesnod:

 

There are two plugs on the rear of the diff. The drain plug is at the bottom and the fill plug is at the top. I believe that they're 10 mm hex. Just park the the car on level ground and remove the one on top. If it's over-filled the excess fluid will drain out. Proper fluid level is to the bottom of the threads. Also be sure to clean the excess fluid from the outside of the diff case or it might appear that you still have a leak when you don't.

-Blackjack :flag

 

Mine stared at about 8600 miles also.
First a few drope and then more. Three rounds at the dealer
and after the third (cover and seal, left side, and arobic sealer)
and it leaked again.

But after two weeks, it stopped leaking...I figure they overfilled it.
So far, so good.

...GeorgeC

 

This is odd, mine started at about 7k miles! I'm going to bring it in anyways.

 

Just bring it in. The quicker you can get it fixed and documented the better. The problem with assuming that it is just overflow is that when you drive it you have no real way of knowing just how much has leaked out!? Then if and when you fry your rear differential due to lack of oil, what do you think the warranty folks are going to say? You saw no signs?

Mine started leaking at the 32k mark just after or during a 3500 mile run through the USA SW desert. They fixed it after two visits, but at 36280 miles, 280 miles after the warranty was over (naturally) it started to leak again. They covered it under warranty because it was documented and fixed during the warranty. Run, don't walk your car to the dealership! :D


[Modified by ruking1, 12:53 PM 8/8/2002]

 

Blackjack,

Thanks again for the pointer. I think I found the fill plug, but for the life of me, I have no idea how to get a wrench or socket on it. It was all I could do to fit my hand up there. It was just to the right of center (looking at diff from rear). At any rate, after more careful inspection with the flash light, and running my hands over the surfaces of the diff, I am 99 percent sure it is the gasket on the left side. That is where the oil is most concentrated. I don't think this could have come from the vent tube as there is no oil higher on the diff, so off to the dealer I go.

As an aside, don't know if many of you have noticed or not, but the external "casting" for the deep center storage compartment is sort of interesting from underneath. First I notice it's stamped with Made in the USA. :flag OK, that's not so strange, but what is is that further in (as the cargo compartment slopes upward), it is also stamped with the corvette name, and the logo (like on the hood and decklid). How about that! :cool:

 

I had the driver's side short shaft seal leaking on my '00 coupe around 13K miles. It took three trips and two dealers to fix it, but she's dry as a bone now. :cool:

 

I've had the left seal replaced on both of my C5s. It is a common problem.

 

Well, my 2000 C5 convertible developed a "rear end leak" last week too. She has about 14,000 miles on the odometer. Took it in to my dealer this morning and it was diagnosed as needing a left axl seal and O-ring. Parts on order for tomorrow. Service writer says it's time to start stocking those parts. "It's the fourth one they've seen in the last two weeks"!.............Corvette Carol's duty driver.

 

Sorry about the leak. Have them fix it and make sure they use the correct sealer on the gaskets or they will have to do it again. Mine had to be fixed on both sides and then the transmission gasket started leaking so it went in for the third time. I hope yours is not so hard to fix.

:eek: :eek: :eek:

 

All,

Thanks again for all the great replies. I am going to schedule an appointment for next week. Sort of frustrating to hear that in nearly every case, it has taken 2-4 trips to the dealer to get this resolved. Hopefully this won't be the case for me as we've got a GREAT corvette tech (David F) at Tom Jumper in Atlanta.

 

My 2000 vert with 14000 miles started leaking in the rear last week. I took it in and they found the left axle seal and O-ring was leaking. When they pulled the axle they found it was worn allowing it not to seal. They ordered a new axle and Im suppose to pick it up today. We have a car show in Paducah Ky on saturday and I hope it is ready. :seeya

 

Here is a pic of the fill plug on the rear diff, you can see where mine was leaking at 11,500 miles: