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Took the car in to diagnose noise in the rear end. Technician rode with me and heard the noise which is audible when making tight turns at low speeds. I was advised that this is a known issue with the car and that it is not going to be a performance issue. He told me that even if they rebuilt the rear end the noise could persist or return. He advised to drive the car more often and when possible make tight figure eight turns in a parking lot to try and lubricate the discs in the rear diff. Does all of this sound reasonable? This is my first Corvette. Tech said he has 12 years of experience working on Corvettes and that the C6 version had a similar issue. Should I ask that the rear end be rebuilt or just live with the noise? What is the correct gear oil for the rear end? Thanks.
Last edited by rmorin1249; Apr 17, 2019 at 03:21 PM.
Is this different than the clunking that takes place when making tight turns when cold? I thought that was more caused by tire judder, and documented in here a fair amount.
Sorry to hear you're having that difficulty, but if it's not the noise I just described (more of a physical feeling than a noise) then I don't have it in my C7 nor did I in my C6.
Is this different than the clunking that takes place when making tight turns when cold? I thought that was more caused by tire judder, and documented in here a fair amount.
Sorry to hear you're having that difficulty, but if it's not the noise I just described (more of a physical feeling than a noise) then I don't have it in my C7 nor did I in my C6.
Randall, I know you have had some aggravating problems with that car, and I hate to hear you have another. He was right when he said the C6's had that problem (the C3's had it also), but it could be cured with new diff fluid and a friction modifier. So, I call BS when he says it's the same if he doesn't even know what fixed the C6's. And figure eights would now cure the the C6 after it started, so he's off base there also. He may have 12 years in, but he surely doesn't sound like an expert.
When you say noise does it sound more like a skipping/jumping/popping like noise. If so it is the clutches, and I would suggest you push the knucklehead to change the fluid, check the seals, and add some friction modifier before you let him tear into anything. From my experience with the C3's, and C6's it will not get any better, only worse. Now I'll admit I may be wrong here, but I ain't betting I am. Good luck my friend.
Jim
Last edited by Rebel Yell; Apr 17, 2019 at 04:15 PM.
I just talked to the service Manager. They are going to change the fluid on Monday. I am to drive it for several hundred miles. If the noise returns they will either rebuild or replace the diff. I have to pay for the fluid change but any repair or replacement will be warrantied.
Last edited by rmorin1249; Apr 17, 2019 at 05:04 PM.
I just talked to the service Manager. They are going to change the fluid on Monday. I am to drive it for several hundred miles. If the noise returns they will either rebuild or replace the diff. I have to pay for the fluid change but any repair or replacement will be warrantied.
I hope the fluid change takes car of it for you Randall. Please keep us updated.
Just picked up my car and the noise is still there and in fact may be worse than when I took it in. They told me to drive it for "several hundred miles" to see if it goes away. The dealer used a BG product rather than ACDelco gear oil. The Corvette tech said they have had good results using this product. I will update this thread after I have driven several hundred miles. I was told the next step would be to rebuild the diff first as GM is not likely to authorize a new diff until a repair is attempted. I have over a year left on my drive train warranty and then another 2 years on my GMEPP Platinum warranty. Pretty frustrated at this point.
The Corvette tech that worked on my car recommended finding an empty parking lot and doing tight figure eights. How does this help? How many should I do and is it something I need to do more than once? Thanks.
The figure 8s are just to exercise the differential with several left and right turns. This probably helps distribute the lubrication. I would guess a half dozen relatively tight figure 8s should be enough. The key is that the gear oil used has the correct amount of limited slip friction modifier additive.
Note that the AC Delco label says "Contains Limited Slip Friction Modifier."
Well the dealer decided to use BG gear oil. I hope they know what they are doing. If the noise persists it's going back before my drivetrain warranty expires.
The Corvette tech that worked on my car recommended finding an empty parking lot and doing tight figure eights. How does this help? How many should I do and is it something I need to do more than once? Thanks.
Doing the figures eights was what I was told to do after changing the gear oil in my C3's. I usually did 4-5 just for good measure. Like Ron I'm guessing that was to get a good coating of the friction modifier on the clutches. I don't know that for sure though. You never know, that may help yours. Hope so.
Last edited by Rebel Yell; Apr 24, 2019 at 07:06 PM.
I don't think you ever stated what the noise was. If I recall correctly, my 2006 made popping noises. A fluid change with friction modifier cured the problem.
I would insist on the correct ACDelco gear oil with Limited Slip Friction Modifier at their expense before letting them tear into your differential.
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Noisy rear diff clutch discs?
