I'm a newbie to this board but I been reading it for two years now. I've seen the past posts on this issue and I'm mad as hell about it since just on schedule, my 2003 at 4100 miles developed the drivers side differential leak. Kinda makes me want my 1991 vette back. Here's a few observations:

1. Mine started when it got hot and at 4100 miles.
2. I checked the fluid level and it was just slightly overfilled. It also appeared that there was hissing when I unscrewed the fill plug. Maybe just my imagination.
3. Went to the Dealer and the Service Assistant new of this problem and said they repaired two last week.
4. It appears to me that an abnormal number of 2003's have this problem.
5. I called the hotline and got a case number for this problem since I doubt it can be repaired easily. This triggered a call to the Service Manger who called me and said he didn't know of this differential problem with vettes! It went back and forth and I finally got a case number and said I was dissatisfied with this car. Just received a letter from the GM rep to call the BBB hotline on this for arbitration.

Getting back to possible causes:

1. Bad O ring
2. Heat or chemcal attack on the O ring.
3. Possible crack or porosity in the casing and or side cover causing a pathway around the O ring.
4. Pressurized casing.
5. Thermal/mechanical affect on the side cover or casing causing a lack of compression on the O ring.

Questions:

1. Has anyone that replaced the O ring seen any nicks, cuts or a compression set on it?
2. Is the vent on top of the unit just a vent pipe or is there a check valve?

Note: The Dealership only wants to replace the O ring and not put the RTV gasket sealing around the side cover face. I told them this is unacceptable since the O ring is new in it now and will leak again if this is all that is replaced.

Side Note: I just got a recall on my 2002 Monte Carlo for a possible coolant leak! They will replace a couple of throttle body fasteners and place some sealant in the radiator!!! If they can have a recall and fix for a $25000car why not one for a $50,000 one?

This has left a very sour feeling with me about GM. Please call that GM phone number and report this.

 

The coolant leak on your Monte is fixed by replacing 3 nuts that hold the throttle body to the plenum with new ones that have washers on them. We drop tabs that amount to more than stop leak in the radiator. I did 3 cars yesterday. It pays me 0.3 HRS or 18 minutes to do the recall on your Monte.


The problem on the vette is not limited to the 03s.
To do it, you need to do alot more than 3 easy to get to fasteners. Under warranty book time I think it pays me 2 or 2.5 hours to do both sides.
Its on about every C5.
Its allmost allways on the drivers side.
Its not an O ring.
Its an actual seal...a metal housing with a rubber seal that has a spring wrapped around it to maintain tension.
Many times it really is just a little bit of excess fluid in the casing coming out the vent.
I've never seen a rear end burned up or dangerously low on fluid from the leaky butt syndrome.
I know its annoying but you stand a much better chance of having your steering column lock up on you [all 6 speeds, pre 02 autos] than you do of having any damage done to your differential from the leak.

 

Had my rear seal replaced 3 times ,then GM/Chev.decided to replace complete rear carrier unit 1500 miles later replacement carrier unit failed,full of metal ,service tech said I was 5 miles from total shut down. 6500 miles 3seal replacements and 3 complete carriers units. GM offered 24mos extension to my warranty and free tire rotations,how often do you rotate tires on a C5.

 

The rear-end leak seemed to be more of a post 99 and up situation.

I don't recall it to be problem for the first year 97's and then 98's.

I also never heard a definitive reason from GM/Chevy to what exactly
the failure is/was. Was it the 'seal', or the installation, or simply overfilling.

I ran my 2.73 rear-end to 65k miles leak free, then replaced it with 3.42's,
both manufactured by Getrag(GM's gear supplier for all C5's) and haven't
had any leaks.

The rear-end leak is certainly a quality-control issue. :yesnod: :cheers:

 

Welcome to the Forum. Sorry about the problem; have it fixed AND insist on the sealant! Good luck. :)

 

I would not immediately chalk this issue up as being a quality control issue, I am somewhat inclined to beleive that this is a design issue!

On my 2000 FRC, I had to have the entire differential assembly replaced at 2000 miles due to the backlash on the pinion gears not being properly set. Thus, I am on my second diff. I changed the fluid to synthetic about 500 miles after the replacement and did not add the friction modifier since the synthetic does not require it. At 36,000 miles, I had noise from the rear end, and not knowing exactly what it was, I added the friction modifier (turns out the noise was due to rust in the half shaft ends at the wheels).

Lo and behold, about 1,000 miles after adding the modifier, the drivers side seal began to leak. When I took the car in to the dealer, they found that the passenger side was beginning to seap a little also. They replaced all of the seals under GMPP.

I know this is only one instance and the connection to the friction modifier is a long shot, but, I have drained the non-synthetic gear lube and once again replaced it with synthetic with no modifier.

I have been told that the problem is due to the design of the seal itself, and the new seals have a slightly different design. This is purely hearsay at this point, but, who knows for sure.

In my business, we would do the required analysis to determine the root cause of the failure and fix it once and for all, as a quality manager, I have found it to be much less expensive in the long run to determine the root cause and fix something once rather than to continually fix the same problem as GM appears to be willing to do. :rolleyes:

 

Yes, I believe it is a design problem with the seal or application of this type of seal. I'm also in an industry (Nuclear) that demands root cause analysis of problems to fix them permanently. On one of the other posts someone said it could be a manufacturing problem of installing the seal. I don't believe this is the cause because it doesn't leak just sitting in the garage and if I take short trips when the differential doesn't heat up much.

A friend at the plant has a 99 that does the same thing. He is just letting it leak.

I can definitely see the oozing from the seal plate to casing interface when hot. It still seems like it's something to do with heat. It is not coming out of the top of the unit.

Still have these two questions:

1. Is the vent a valve or just an openeing?
2. The people that have removed the seal (thought it was an O ring) is there any damage on it or degradation?

When I take my Monte Carlo in this Friday for its recall I'm going to talk to the Corvette Mechanic about how he is going to attempt a fix!

Note: I'm worried that the C6 which I thought about buying in several years will have this same GETRAG unit and potentially the same problem.

 

I can tell you it deffinitely IS a problem on 98's as well. This week I just had my second seal in 6 months replaced. $500 damn dollars! each time! What's up with this? So far the 03 Z06 has not leaked (2,000 miles) But then again, why would it...it's still under warranty.

 

I have read nearly all the posts on this subject. Getrig mistakenly made the depth of the area around the gasket to deep so the side plate can't press against the gasket with enough pressure to prevent leaking.

I think the reason GM has not addressed the issue is that they have always manufactured cars that leak oil and does not want the Corvette to be the only exception. In all honesty, they do not consider nuisance leaks relevant. The cost to have Getrig re-tool may cost more than it will cost to fix the handful of us folks on the forum that want it fixed. In addition, GM wants to give us a reason to spend our money to have it fixed after the warranty expires. It’s like putting high graphite brake pads on the car that wear out fast. They are looking to us to spend some money to help support their dealerships. Built in obsolescence still prevails. Two decades ago junkyards were full of GM, Ford, and Chrysler cars with 50,000 miles on them. Boy, have they come a long way since then? Here is a statistic for you. A full 80% of all Mercedes Benz vehicles ever built dating back to 1895 are still licensed and drivable today.

Lastly, I too have a letter in my file inviting me to arbitration on the issue. We should not have to put up a fight in order to have a car that does not leak oil.
:smash:

 

Yea, I think this whole leak situation is BS!!!!! :mad A $50k car should be perfect in my opinion.

 

There are 2 kinds of C5 differentials. Those that have leaked and those that are going to leak. Hey, it's Chevrolet.

 

Mine started leaking at, about 9,000 miles. I had it fixed under the warranty.

 

Okay gang, we need to get more specific, since there're TWO carriers for non-Z06 cars: the 2.73s and the rest, which comprise all MN6s and 3.15A4s.

My diff had an oil film around that area when I installed the exhaust, but attributed that to carelessness when filling the diff. After all these comments, will check it again soon. Since I cleaned it up, it shoudl be obvious if it's leaking.

Just wanted to know if ALL carriers are likely to leak, or just the more popular 'upgradeable' kind.

Thanks.

JC

 

Not your imagination.. Mine did this too when I opened it to change the fluid. I've not had any leaks on mine (98). If you're right about the check valve, it makes sense that their would be a vacuum in the case when cold.

 

If Getrag did mill the groove too deep why hasn't GM come up with a thicker seal?

Mine is an A4 3.15, my friends 99 is a MN6 3.42 both leak.

Maybe GM should connect a tube from the manifold to the differential vent and suck a vacuum on it! That would probably stop it!

 

Hey its chevrolet ...made in Germany!

 

How big of a leak are we talking? Does it leave puddles? Single drips? Nothing?

The rear of my 2000 SS has always leaked. You can see the leakage on the housing, but I never cared. It never left a drop on the highway so it's not a problem. I changed my rear end fluid and it was completely topped off. Unless you've got some kind of show car where you want the underside to look perfect, I wouldn't sweat it.

Dope

 

I just personally replaced the left side cover on my 2003 with 9000 miles and thoroughly examined the old cover and could find no visable problems with the part. The new cover came with a new O-ring and axle seal installed so all I had to do was replace the cover and use a small bead of RTV sealer around the perimeter of the cover mating surfaces and around the O-ring groove. I have driven about a hundred miles since the repair with no leaks and really do not anticipate any. I added the factory recommended synthetic lube along with a 4 OZ bottle of the Posi lube. I was really pissed about the prospects of having my new baby scattered all over the shop but it really is a simple job to do and I have faith in my repair. There are plenty of other expensive brand cars with much more serious defects than our Corvettes. Most are German too!

 

My '99 has been in twice to have the leak fixed -- at about 7000 miles and at about 17,000 miles. :mad It leaked enough to leave drops on the garage floor. I took it to a different dealer the second time and the service manager promised me it would not leak after they fixed it! It now has 21,000 miles and is still leak free.

I would not take it to a service department that is not familiar with this problem -- such a service department is not familiar with C5 Corvettes!

Oh, and in my book you would have to be a dope to pay over $40,000 for a car and not "sweat it" when it leaks on your garage floor! :D

 

40k isnt all that much for a car now a days. Check prices on a new Toyota landrover or sequoya...$40k for a Camry on stilts. You get performance that equals or bests cars cost 2 and 3 times as much for this kind of money and people complain about a couple drops on the garage floor. If rearends were blowing up due to low fluid left and right I could see GM doing a recall but they arent blowing up, they're just blowing by the competition and still people complain.