When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I was recently informed by a Mechanic at a Chevy Delaership here in Cincinnati that my differential has developed a leak on the left side on my 99 Mn6 vette. This vette has 12,000 miles on it. I know this is a common problem on the C5.
The mechanic wants to repair the leak and I certainly want to also.
He said he would advise replacing all the seals on the Diff. for around
$ 900.. Do you think it would be advisable to replace all the seals or just relace the one that is broken?
I want to do what is right, but I also only want to spend what I need to. Any thoughts would be appreciated. Thanks, Dave
I'd only go with the leaking seal since the mileage is so low. I haven't heard of the other seals going bad. The only other seal that could be questionable is the O-ring on the left side cover.
Usually only one side leaks, other side is rare from what I have seen. How many have they done and what is their success? If this is rare for them to do, I would hesitate having them all replaced. I think the left side can be done with the rear still in the car, but all of them is likely removal and that would really push the bill up.
From: AKA Harvey Mushman-I know just enough to be dangerous "Those who sacrifice liberty for safety deserve neither"- B. Franklin
Senior Member
Cruise-In V Veteran
That's . Why fix everything that's not broken? For all you know he could screw up the gear settings and you'll have bigger problems. Half of the C5s out there have a rear that leaks on the left side. Mine was done once under warranty. If it leaks again I will DIY. Here's a link: http://www.cajundude.com/outputshaftseal.htm I'll see if I can look up the updated GM bulletin.
Edit- Here it is.: http://www.corvetteactioncenter.com/....php?qstId=225
Usually only one side leaks, other side is rare from what I have seen. How many have they done and what is their success? If this is rare for them to do, I would hesitate having them all replaced. I think the left side can be done with the rear still in the car, but all of them is likely removal and that would really push the bill up.
They should be able to replace that seal without pulling the torque tube, tranny and cradle so you should save some bank by only replacing the needed seal. This guy needs to get his wife a good christmas present...and he wants you to pay for it.
I have been through this (7) times with my 2000 Coupe now with 23k miles. It started at 4500 miles and has been consistently failing on average every 3000 miles. The L axle and housing seal has been the site of the leak every time. The L axle cover has also been replaced one time. The most recent repair included both seals (new improved seals and different P/Ns than previous) and an anaerobic sealer (red) for the housing. You should make sure your shop is up to date on this by having them consult w/ the GM tech line. As far as the price, ask; what is the hourly labor rate, how many hours are they charging you and why (check labor times at www.alldata.com), and what are the P/N’s and how much are they. They probably just asked a tech how many hours her wanted to charge and did not go by the book. Good Luck!
Notice that the bulletin above is just for the RIGHT side cover ... not the left. I really haven't heard of anyone having issues with the RH cover leaking.
You have one other option to consider, since you are out of warranty anyhow and need to pay for the repair. DTE does a basic Stage I build (see their web site) and I think they have better success fixing the leaking issue. You could pick up a unit from DTE, replace the whole rear (about $300) and then use yours as a core. Contact DTE and get their input as well, they probably work on more of these differentials than anyone in the USA.