Rear Diff Groan 2018

jcor3 · 08-02-2018, 11:23 AM

2018 2SS with Mag Ride, NPP, auto trans

I picked up the car May 23 and have driven 7500 miles. I started to hear the rear differential groan on cold turns a few weeks ago. Talked to the dealer and was given the typical bs, normal, bring it in, no bulletin on the 2018, etc.

Yesterday the car was in for my free oil change. I listed exactly what the problem was on the online scheduler. The service intake guy tried to change what I had listed. Anyway, took the technician for a drive and couldn't duplicate due to the dealer being 40 miles from home and the car was warm.

They let the car sit until lunch and were then able to reproduce the differential groan.

Get this: There is no fix. (Even though there was a fluid flush service bulletin on the 2017 and 2016's) My car is now an official GM guinea pig.

"PEI0465: "Engineering Information - Cold Moan from Rear Differential on Vehicles that Have Never Had a Rear Differential Flush (May 29, 2018)"

GM wants data, said another way, they are tracking my car now they will know how long it takes for the differential to fail.

The Engineering INfo doc states clearly that the tech was supposed to call the engineers with the phone numbers listed and document that on the customer file. No surprise there is no such record on my docs.

To the point, I bought a car for nearly $50k that sounds like the rear end is going to fall apart every morning. GM knows about it and doesn't give a shit, and they are clearly hoping to stall me until the warranty expires. BTW, the warranty will expire the day before the diff does....

torqueaddict · 08-02-2018, 09:43 PM

Dealers are flushing or replacing the diff. That's the fix. Leave that crappy dealer and go to another one.

camaro5 · 08-03-2018, 11:47 PM

Put some Amsoil gear oil in with a bottle of lsd additive

len_eng · 08-04-2018, 08:45 AM

I had the same issue and brought it in this week. The receipt states that there was a TSB #17-NA-287 that covered the issue and they replaced the gear oil.

Marco Falcone · 08-21-2018, 06:01 PM

My 2018 2SS Vert has the RD groan. Started at maybe 1800 miles. Thought it was a tire issue. Then it went away, Now with about 2700 miles on the car, it’s back. Only when the car has been parked overnight/several hours and is cold. Goes away after a few minutes/few turns.

I went to my dealer. Told the Service Manager Greg about it. He said it happened on some of the Camaro’s and Vette’s, but it was not common. He said he was aware of a TSB about it and told me to bring it in whenever was convenient and they would flush and refill it, under warranty and the TSB. (I told him which one, 17-NA-287.) He punched some keys on his computer and said that was the right one. He added it would be documented in my service file in case there were any other problems after the service. I made an appointment for this coming Thursday. He said they would try and get it done in an hour or so.

Hopefully this will solve the issue.

Really happy with my dealership so far. No argument, no discussion. Just “Yes it can be a problem, sorry we will fix it at your convenience.”

Same attitude as when I asked for them to install a Dimple magnetic oil plug on delivery. (SM: “Good idea. I use those, too.”). And when I came in for my first free oil change at 500 miles. (SM: “No prob. I wish more people knew how to take of a new performance car.”)

Hopefully the dealership stays this way!

Rock-It Man · 08-21-2018, 07:51 PM

This one of those subjective problems. Some groan is inevitable in a cold limited slip differential, but how much is too much?

If it happens only when cold and there's not thumping or snapping, I would not get bent out of shape if a flush doesn't fix it or if it come back soon after a flush. That would be an indication that you are too sensitive to a normal feature of this device.

Gunmetalmissle · 08-21-2018, 07:58 PM

Long story short my diff had cold morning groan. I just recently replaced it with leftover fluid I had from my G8 GT. If you are not familiar with the G8 fluid it is the super expensive Castrol carbon mod saf. Three mornings in a row I have been groan free. I need to drive it a few hundred more miles before making a definitive conclusion but so far it seems to have fixed the problem.

aldaran · 08-26-2018, 01:39 PM

Mine has it, but only on cool mornings, but I don't hear any thumping that would indicate any issues. My commute is 10 miles and don't hear it anymore after that first turn in the morning.

Azerlazer26 · 09-11-2018, 11:22 AM

My 2018 2SS is now starting to make this groaning noise :( any word if GM finally got a TSB for this issue for the 2018’s yet? Also to everyone here that has gotten this issue resolved, how has your diff acting?

torqueaddict · 09-11-2018, 12:13 PM

Quote:

Originally Posted by Azerlazer26

My 2018 2SS is now starting to make this groaning noise :( any word if GM finally got a TSB for this issue for the 2018’s yet? Also to everyone here that has gotten this issue resolved, how has your diff acting?

I'm assuming the weather temps there are starting to dip? Seems to be more of a cold climate issue. Sucks that it happened on your 2018. What's your mileage?

VinnAY · 09-11-2018, 12:27 PM

I haven't noticed any of this on my car, so far...Mar 18 build date. I don't if I'm usually on the throttle enough with the exhaust in Track Mode to disguise any minor noises.

Azerlazer26 · 09-11-2018, 01:01 PM

Quote:

Originally Posted by torqueaddict

I'm assuming the weather temps there are starting to dip? Seems to be more of a cold climate issue. Sucks that it happened on your 2018. What's your mileage?

Just about to cross 4,600

Azerlazer26 · 09-11-2018, 01:03 PM

Quote:

Originally Posted by VinnAY

I haven't noticed any of this on my car, so far...Mar 18 build date. I don't if I'm usually on the throttle enough with the exhaust in Track Mode to disguise any minor noises.

I’m always on the trottle and have my exhaust set in track just so I can hear those aggressive pops from a cold start. I hope it’s just the diff fluid causing this issue.

Wyzz Kydd · 09-11-2018, 01:15 PM

My 2016 SS had it. I took it in, they changed the diff fluid and I drove it for another 30K + miles with no groaning.

08-03-2018, 11:47 PM	#3
camaro5 Drives: X-15 Velocipede Join Date: Mar 2008 Location: SW Florida Posts: 4,637	Put some Amsoil gear oil in with a bottle of lsd additive __________________ Go from the presence of a foolish man, when thou perceivest not in him the lips of knowledge General Motors ASEP, A.S. Automotive Technology, Telecommunications Specialist, CISCO Network Engineer STANDARD DISCLAIMER camaro5 is furnishing this information "as is". camaro5 does not provide any warranty of the information whatsoever, whether express, implied, or statutory, including, but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the information will be error-free.

08-21-2018, 06:01 PM	#5
Marco Falcone Drives: 2018 2SS Convertible MBM/Kal Join Date: Feb 2018 Location: California Posts: 162	My 2018 2SS Vert has the RD groan. Started at maybe 1800 miles. Thought it was a tire issue. Then it went away, Now with about 2700 miles on the car, it’s back. Only when the car has been parked overnight/several hours and is cold. Goes away after a few minutes/few turns. I went to my dealer. Told the Service Manager Greg about it. He said it happened on some of the Camaro’s and Vette’s, but it was not common. He said he was aware of a TSB about it and told me to bring it in whenever was convenient and they would flush and refill it, under warranty and the TSB. (I told him which one, 17-NA-287.) He punched some keys on his computer and said that was the right one. He added it would be documented in my service file in case there were any other problems after the service. I made an appointment for this coming Thursday. He said they would try and get it done in an hour or so. Hopefully this will solve the issue. Really happy with my dealership so far. No argument, no discussion. Just “Yes it can be a problem, sorry we will fix it at your convenience.” Same attitude as when I asked for them to install a Dimple magnetic oil plug on delivery. (SM: “Good idea. I use those, too.”). And when I came in for my first free oil change at 500 miles. (SM: “No prob. I wish more people knew how to take of a new performance car.”) Hopefully the dealership stays this way! __________________ 2018 2SS Vert. MBM/Kalahari. MRR FS01’s with 285/305 MPS4S. Black Bow ties, A8, MRC, NPP, 6-piston Brembo’s w/ matching rears, OEM Ground Effects/Splash Guards, 8”/Nav. Borla S-type, Pray IM/TB, RotoFab. Past DD’s of note: 2013 Caprice PPV. (“Company” car.) 1998 Cadillac STS 1996 Impala SS 1969 Cadillac DeVille Convertible 1993 Corvette 1991 Mustang 5.0 LX 1973 Alfa Romeo Spider 1986 Mustang GT T-top 1964 Falcon Sprint Hardtop. (First car, still have the key!)

08-26-2018, 01:39 PM	#8
aldaran Drives: 2016 Camaro 2SS/RS Join Date: Oct 2008 Location: Alice, Texas Posts: 579	Mine has it, but only on cool mornings, but I don't hear any thumping that would indicate any issues. My commute is 10 miles and don't hear it anymore after that first turn in the morning. __________________ 2016 2SS: Silver Ice, A8 Auto, Adrenaline Red, Black Rally Stripes, and Black bowties. My Journey..... 1100 Status - 08/17/2015 : 2000 Status - 09/28/2015 2500 Status - 09/29/2015 : 3000 Status - 09/29/2015 3000 Status - 10/19/2015 TPW 11/9 3800 Status - 11/04/2015 Seq: 122808 4300 Status - 12/17/2015 (Charlotte, MI) 4200 Status - 01/08/2016 4800 Status - 01/14/2016 5000 Status - 01/19/2016 6000 Status - 01/20/2016

08-02-2018, 11:23 AM	#1
jcor3 Drives: 2018 2SS & 2002 1500HD Join Date: Jan 2018 Location: California Posts: 9	Rear Diff Groan 2018 2018 2SS with Mag Ride, NPP, auto trans I picked up the car May 23 and have driven 7500 miles. I started to hear the rear differential groan on cold turns a few weeks ago. Talked to the dealer and was given the typical bs, normal, bring it in, no bulletin on the 2018, etc. Yesterday the car was in for my free oil change. I listed exactly what the problem was on the online scheduler. The service intake guy tried to change what I had listed. Anyway, took the technician for a drive and couldn't duplicate due to the dealer being 40 miles from home and the car was warm. They let the car sit until lunch and were then able to reproduce the differential groan. Get this: There is no fix. (Even though there was a fluid flush service bulletin on the 2017 and 2016's) My car is now an official GM guinea pig. "PEI0465: "Engineering Information - Cold Moan from Rear Differential on Vehicles that Have Never Had a Rear Differential Flush (May 29, 2018)" GM wants data, said another way, they are tracking my car now they will know how long it takes for the differential to fail. The Engineering INfo doc states clearly that the tech was supposed to call the engineers with the phone numbers listed and document that on the customer file. No surprise there is no such record on my docs. To the point, I bought a car for nearly $50k that sounds like the rear end is going to fall apart every morning. GM knows about it and doesn't give a shit, and they are clearly hoping to stall me until the warranty expires. BTW, the warranty will expire the day before the diff does....

08-02-2018, 09:43 PM	#2
torqueaddict Drives: Tesla M3 LR-AWD [Former 1SS owner] Join Date: Jan 2018 Location: Miami Posts: 950	Dealers are flushing or replacing the diff. That's the fix. Leave that crappy dealer and go to another one.

08-04-2018, 08:45 AM	#4
len_eng Drives: 2024 Radiant Red 2SS, 1994 Z28, Join Date: Jan 2013 Location: Sharon, Ma Posts: 166	I had the same issue and brought it in this week. The receipt states that there was a TSB #17-NA-287 that covered the issue and they replaced the gear oil.

08-21-2018, 07:51 PM	#6
Rock-It Man 376 cubic inches of fun Drives: 2023 Camaro ZL1 A10 Join Date: Jul 2010 Location: MA Posts: 4,027 View My Garage	This one of those subjective problems. Some groan is inevitable in a cold limited slip differential, but how much is too much? If it happens only when cold and there's not thumping or snapping, I would not get bent out of shape if a flush doesn't fix it or if it come back soon after a flush. That would be an indication that you are too sensitive to a normal feature of this device.

08-21-2018, 07:58 PM	#7
Gunmetalmissle Drives: 16 ngm ss Join Date: Jan 2017 Location: NJ Posts: 233	Long story short my diff had cold morning groan. I just recently replaced it with leftover fluid I had from my G8 GT. If you are not familiar with the G8 fluid it is the super expensive Castrol carbon mod saf. Three mornings in a row I have been groan free. I need to drive it a few hundred more miles before making a definitive conclusion but so far it seems to have fixed the problem.

09-11-2018, 11:22 AM	#9
Azerlazer26 Drives: 2018 Camaro 2SS Join Date: Jun 2018 Location: Michigan Posts: 611 View My Garage	My 2018 2SS is now starting to make this groaning noise :( any word if GM finally got a TSB for this issue for the 2018’s yet? Also to everyone here that has gotten this issue resolved, how has your diff acting?

09-11-2018, 12:27 PM	#11
VinnAY Account Suspended Drives: 18 1SS/1LE Join Date: Jun 2018 Location: Missouri Posts: 939	I haven't noticed any of this on my car, so far...Mar 18 build date. I don't if I'm usually on the throttle enough with the exhaust in Track Mode to disguise any minor noises.

09-11-2018, 01:15 PM	#14
Wyzz Kydd Banned Drives: 2018 Camaro SS1 1LE Join Date: Feb 2017 Location: Georgia Posts: 1,595	My 2016 SS had it. I took it in, they changed the diff fluid and I drove it for another 30K + miles with no groaning.

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