Redc8z06

If nothing else at least check the fluid level. There has been a few reports of some diffs being a little low. Seen it with the Stingrays as well.

racezx9

agreed !!! i have GM extended warranty for 84 months. I have no need to modify, just putting on the miles and follow the owners manual.

0NORCAL-SS

I have another guy coming this weekend. Dealer charged him 150 dollars to change out rear diff fluid and he decided to pass the "great offer" they gave him. Ill try to make a video showing everything to help you guys out for those that want to save money.

2kvetmy

I put about 50000 on my C6,Z51, with Amsoil plus additive; no noise or problems; the additive was a small 4 oz bottle
then I did the suggested figure 8's to get it throughout the discs

0NORCAL-SS

Yeah my amsoil rep said on z06 don't use additive the oil should be fine. Now if I get feedback if there is chatter I'll try the additive. Whenever I change oil I always do figure 8s after by spinning tires lol

Greg00Coupe

I know on my stingray I was getting a check rear end warning........ checked the level it was OK but oil was gritty with 18K miles.

? With the coolers don't we need to bleed the system???? I mean as I understand it when refilling there are lines above the differential which will have air in them????

I thought but could be wrong I saw that when I looked to change the stingray. I traded it a few months later and never changed it.

0NORCAL-SS

Run it in air for 30 seconds open fill to check level and if air us trapped will go out.

davepl

FWIW, at the local neighborhood "old USMC veterans fix really expensive rare cars" shop (everyone needs one) they run them in for about half an hour. Don't know if that's overkill, or maybe specific to older units like the 9-inch, or just a good idea.

0NORCAL-SS

So far no issues on any amsoil rear cars. No chatter at all from diff

Painrace

Changed mine at 500 miles and fluid looked great. No issues. It took 3 quarts to fill.

Jim

jimman

So your saying dirty fluid or fluid breakdown caused this???

lawdogg149

New problem. My trans and rear axel are out getting new seals.

This is a pic of top of rear axel. Seems the vent is spewing alot of fluid which puddles up on top.

I have changed the fluid 3 times already.

FirehawkTA

Thanks for the info, guys. I took my Z yesterday for an oil change and asked them to check the differential fluid level. They said they couldn't do it because the whole rear suspension would have to be dropped. I called BS and the service manger said he looked at it himself. This dealership is approximately top 30 in the country for Corvette sales. Bummer. Just have to do it myself.

Painrace

It took 10 minutes at my dealer. It took longer to go get the third quart of fluid than anything else!

Jim

0NORCAL-SS

Guys remember to run it in gear then refill again after.

TEXHAWK0

My differential was about a half inch low from the factory, so I went ahead and changed mine at about 7000 miles.
Deposits on both the drain and fill plugs.

Bmbarney

That's one way to look at it - get rid of it before the coverage has expired?

One Curve at a time

Change mine at 5k and this is what the oil looked like:




Diff Oil change at 5k

Also my drain plug:




Diff drain plug at 5k

I wish I would have change that oil earlier...

Bill Dearborn

I look at it this way. The car has a 5 year power train warranty and it is unlikely that most original owners will own the car long enough to reach that warranty expiration. Until then they are covered by the factory warranty. If they track the car then they have to follow the recommended track maintenance in the OM which specifies far more frequent diff fluid changes based on hours spent on the track and not miles. From page 9-7 of the 15 manual:
"The rear axle fluid temperatures may be higher than when driving in severe conditions. Drain and refill with new fluid after the first racing or competitive driving event, and then
after every 24 hours of racing or competitive driving. See Recommended Fluids and
Lubricants on page 11-12. " If you aren't tracking the car I don't see any need to change the fluid any earlier than the 45K mile GM recommendation. With the low mileage accumulated on most Corvettes most owners who keep the car 10 years or less will not have the car long enough to see the advantage of more frequent fluid changes.

Bill

Crossofiron

Man, you are 1960s old school with your oil changes. Your money, your car, whatever.