Rear differential whine

2011 CHEVROLET CAMARO
53,000 MILES • 3.6L • V6 • 2WD • MANUAL
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JELLER1
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Hello,

I recently had my car's rear differential fluid changed by a mechanic. After about a week and a half the differential started to produce a whining sound whenever I go through a slow tight turn. I found out from the mechanic that they didn’t add a friction modifier for my LSD. Could not adding this friction modifier produce this problem? Any response would be greatly appreciated.

Thank you,
Jacob Eller
May 4, 2020 at 10:35 PM
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ASEMASTER6371
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Good morning,

That lube should be added as a supplement for the clutches. The clutches have a habit of slipping and will cause a slipping feeling when going around corners or turns as the wheels will be spinning different speeds.

https://www.2carpros.com/articles/how-a-differential-works

As far as causing a noise, no, it will not cause this.

I would have the level verified to be sure the level is correct. At this point, am concerned. The noise is there and will not go away even from low fluid.

https://www.2carpros.com/articles/differential-gear-oil-fluid-check

Roy
May 5, 2020 at 4:07 AM
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JELLER1
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The mechanic is now saying they used Car Quest full synthetic gear oil 685-32 that comes with a limited slip additive pre-mixed. Is a limited slip additive the same as a friction modifier?
May 5, 2020 at 9:40 PM
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ASEMASTER6371
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Yes, it is.

I do not see that in there description.

You can still add it but as I stated, it would have nothing to do with the noise that you have. This additive will not cause any issues. It will keep the clutches from chattering.

Roy
May 6, 2020 at 3:36 AM
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JELLER1
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Thank you for the responses, I found out from the parts department that the gear oil they used is actually a top off oil only and is not supposed to be used as the replacement oil, it turns out the oil is too thick for my LSD and the sound I’m hearing is from the clutch plates not being properly lubricated and why I only hear a whine whenever I do a slow tight turn and not when I’m driving normally down the road.
May 6, 2020 at 4:53 AM
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ASEMASTER6371
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Okay, I would start by changing the oil out of the differential and replacing it with the correct oil. Then add the additive for the clutches as well.

I attached the fluid required for you and the GM part number for the fluid as well as the additive.

Roy
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May 6, 2020 at 5:05 AM