[Driski]

I had the groan, waited until the fall to bring it to the dealer. Dealer replaced the entire unit. I had to leave the car for a few days waiting for the part to arrive. I have driven it at least 10 times in the morning and it no longer makes the noise. It is put up for the winter now but I have confidence I will be able to put this problem in the rear view mirror. Good Luck to all who are having this problem. Be patient and persistent and it will get done.

[BriGuy]

#14-04-20-001A: Moan from Rear Differential During Low Speed Tight Turn Maneuvers - (Dec 9, 2014)

Subject:

Moan from Rear Differential During Low Speed Tight Turn Maneuvers

Models:

2014-2015 Chevrolet Camaro Z/28



This Bulletin has been revised to add the 2015 Model Year and add a Note. Please discard Corporate Bulletin Number 14-04-20-001.
Some customers may comment on a moan coming from the rear end during low speed tight turn maneuvers.
The Chevrolet Z/28 Camaro was designed to be the ultimate track-capable Camaro and has features and equipment that are not shared with other Camaros.
As an example, power is distributed to the rear wheels via a limited-slip differential featuring a helical gear set, rather than traditional clutch packs. The new design enables the driver to apply more power and get through corners faster, by continuously adjusting the torque bias to maximize available traction.
The differential works in unison with Chevrolet’s proprietary Performance Traction Management system, which allows drivers to adjust the level of throttle and brake intervention to match their capability and driving environment.
Adding Friction Modifier to the Rear Differential to Reduce the Moan
This is considered a normal characteristic refer to the information below ONLY if the customer desires to reduce the moan.
This can be accomplished with the addition of a friction modifier to the rear differential lube.
Note: To add the friction modifier, perform the following actions:
1. Raise and support the vehicle. Refer to Lifting and Jacking the vehicle in SI.
2. Remove the rear differential fill plug. Refer to > Differential Oil Replacement (218 mm - Z/28) in SI.
Notice: Prior to adding the limited-slip axle additive, the bottle MUST be shaken vigorously for at least one minute to mix the additive thoroughly, then immediately poured into the differential.
3. In the United States, add 2 oz of P/N #88900330 LIMITED SLIP AXLE LUBRICANT ADDITIVE to the differential.
In Canada add 59 ml of P/N #992694 ADDITIVE, L/SLIP AXLE LUBRICANT to the differential.
4. Test drive the vehicle and apply 3 full lock-to-lock turns in 2nd gear with light throttle application in order to determine if the moan is gone.
o If the moan is still present, add an additional 2 oz (59 ml) and then reevaluate. It is not recommended to add more than a total of 4 oz (118 ml) to the base lubricant.
Removing Friction Modifier From the Rear Differential
It is possible that after adding the friction modifier and driving their vehicle, the customer may become dissatisfied with the vehicle track performance.
o If the driver wishes to return the performance to the levels prior to the addition of the friction modifier then perform the following actions:
1. Drain the rear differential fluid.
Notice: Initial noise may return after flush and fill.
2. Flush and fill the rear differential with the proper fluid.
Parts Information
 

Part Number

Description

88900330

LIMITED SLIP AXLE LUBRICANT ADDITIVE (U.S.)

992694

ADDITIVE, L/SLIP AXLE LUBRICANT (Canada)

88900401

LUBRICANT - REAR DIFFERENTIAL SAE 75W90 (U.S.)

89021678

LUBRICANT - REAR DIFFERENTIAL SAE 75W90 (Canada)

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

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© 2016 General Motors. All rights reserved.

[Driski]

[QUOTE=wooshman24;9454813]Guys, is this the sound you're talking about? I might have the same issue :(

Sorry, I cant make it out in the video. I know that when I had it in my car it was kind of hard to hear. However, I could actually feel it in the seat. If you think you have it I would suggest you bring it to your dealer and let them go through the process of replacing it.

Wait, just turned up the volume. I can hear it now! Get it fixed.

[glenB]

Has anybody had the diff feel like a snap loose with a glunk on hard turns, under power after about 10 min from start up?

It enters the turn fine, but then at the apex it feels like the rear sways and there's a clunk. I will only do it once. If I had to hazard a guess it's like the clutch pack releases and it cause the rear to shift when it does, with a clunk.

[Rydfly]

I dealt with this for months . I had the rear end growl at cold start . FINALLY ! they changed out my rear diff with an updated clutch system they said. So far no noises at all .

I think this will be a recall eventually. Don't do a fluid swap , just get the dealer to give you a new diff.

[CAM-FIFTY]

Originally Posted by Rydfly

I dealt with this for months . I had the rear end growl at cold start . FINALLY ! they changed out my rear diff with an updated clutch system they said. So far no noises at all .

I think this will be a recall eventually. Don't do a fluid swap , just get the dealer to give you a new diff.

Can you post a snippet of your dealer's service order?

[TwistedLT1]

There's a TSB out for this. It's #09-04-20-001E. It addresses these problems as it's been very common. Best hope is GM honors the warranty though. Myself and others GM says they will not fix.

[TwistedLT1]

Originally Posted by Rydfly

I dealt with this for months . I had the rear end growl at cold start . FINALLY ! they changed out my rear diff with an updated clutch system they said. So far no noises at all .

I think this will be a recall eventually. Don't do a fluid swap , just get the dealer to give you a new diff.

Can you PM all the info regarding how you got yours done and what the dealership had told you?

[Masa]

Damn that sucks.

I just started having the issue myself on my 2017 2SS two weeks ago after about 1500-2000 miles. In the shop now.

Seems a lot of guys are replaced fluid and sometimes it works, other times it doesn't. Some have had the diff replaced as well.

They better have a fix for this....the sound is terrible and very loud. Not anything you would even consider tolerating in an expensive new car.

Originally Posted by xonos

Bad news. They did the "fix" and it's come back and it's even worse. I am taking it in to get them to look at it again. :(

[Nick1297]

Originally Posted by ChipperG

I have a 2016 1SS at 1900 miles the rear end started to make noise and was replaced under warranty. I did a fluid change at 1400 miles. 600 miles later the rear end broke the gears and it was towed to the dealer again!!! I do not do hard launches but I do drive it pretty hard. Is anyone else having this problem?

I have a 2016 2SS with 14,394 miles on it. In August of 2016 I took my car to the dealership with 10,146 miles because I noticed smoke coming from my tailpipes and oil covering the rear of my car. Dealer looked at the car and said "Checked for leaks, none present, but the vehicle was 1/2 Qt Low". I was given the car back the same day. Went back two weeks later with 10,611 miles and was told that the differential oil cooler outlet hose had a "poor fit". They replaced it and returned the car back to me 8 days later. I still continued to notice the smoke coming from my tailpipes and the oil on my rear so I went to the dealership numerous times just to be told "don't worry about it its just burning off the rest of the oil that leaked before the repair". I stupidly listened to what they said. Then in October I brought the car to the dealership again, this time with 12,360 miles because I was still having the same problem but now I was also having transmission issues and a horrible engine whine. The car would not go into gear at some points. They said they found the mainshaft bent and since GM was not in production with the parts needed to fix the tranny they just replaced the whole transmission and returned it to me almost a month after. Then December came. The car has 14,353 miles on it. The car STILL continues to leak oil. The dealership looks at the car for just a few minutes and tells me the car is leaking rear differential fluid from several seals and fittings and then told me that my "rear is shot" and said they weren't going to cover it. BECAUSE MY TIRES WERE LOW ON TREAD. The car sat there till February and then I decided to take the car and have someone else fix it because I was fed up with Chevy. The day I pick up the car while on the highway just cruising I decide to downshift to 4th and it would not go in. I was locked out of all my gears! I finally got the car into 4th just for it to suddenly pop out a minute later. I then put my clutch in got my car into 3rd but my clutch would not come back up. I painfully smelt the burning of my clutch, pulled over and turned off the car. I then had the car towed from a nearby spot right off the highway back to the dealership. They looked at the car and all of a sudden I now I have no fourth or second gear. And they still refuse to cover it because of some bald tires. What do I do? I love this car but I can't deal with the stubbornness of GM. PLEASE HELP!

[Patrickson13]

Having this same issue right now, GM wont do a thing about it. They're claiming that this is not a common issue with this model car and won't honor the warranty. The customer service line nor the executive office are doing anything to help.

[Tridon]

Is this an issue that is exclusive to the SS. I have a 6M V6 and wondering if I should be concerned as well and get the diff flushed?

[TybeeSS]

Originally Posted by Nick1297

I have a 2016 2SS with 14,394 miles on it. In August of 2016 I took my car to the dealership with 10,146 miles because I noticed smoke coming from my tailpipes and oil covering the rear of my car. Dealer looked at the car and said "Checked for leaks, none present, but the vehicle was 1/2 Qt Low". I was given the car back the same day. Went back two weeks later with 10,611 miles and was told that the differential oil cooler outlet hose had a "poor fit". They replaced it and returned the car back to me 8 days later. I still continued to notice the smoke coming from my tailpipes and the oil on my rear so I went to the dealership numerous times just to be told "don't worry about it its just burning off the rest of the oil that leaked before the repair". I stupidly listened to what they said. Then in October I brought the car to the dealership again, this time with 12,360 miles because I was still having the same problem but now I was also having transmission issues and a horrible engine whine. The car would not go into gear at some points. They said they found the mainshaft bent and since GM was not in production with the parts needed to fix the tranny they just replaced the whole transmission and returned it to me almost a month after. Then December came. The car has 14,353 miles on it. The car STILL continues to leak oil. The dealership looks at the car for just a few minutes and tells me the car is leaking rear differential fluid from several seals and fittings and then told me that my "rear is shot" and said they weren't going to cover it. BECAUSE MY TIRES WERE LOW ON TREAD. The car sat there till February and then I decided to take the car and have someone else fix it because I was fed up with Chevy. The day I pick up the car while on the highway just cruising I decide to downshift to 4th and it would not go in. I was locked out of all my gears! I finally got the car into 4th just for it to suddenly pop out a minute later. I then put my clutch in got my car into 3rd but my clutch would not come back up. I painfully smelt the burning of my clutch, pulled over and turned off the car. I then had the car towed from a nearby spot right off the highway back to the dealership. They looked at the car and all of a sudden I now I have no fourth or second gear. And they still refuse to cover it because of some bald tires. What do I do? I love this car but I can't deal with the stubbornness of GM. PLEASE HELP!

This is crazy. At14k miles most of our cars will have low tread. These tires dont allow for 30-40k miles. If it were me, I would replace the tires if the car is drivable and bring it to another dealership. That or call GM customer care.

[jw0287]

Originally Posted by wooshman24

Guys, is this the sound you're talking about? I might have the same issue :(

That's what I am having. Tomorrow I am leaving my car at the dealer overnight so they can start and run it in the morning.

They had it last time and did nothing.