Strake

If I'm understanding what you are asking, then I did....

As the one who originally posted on here about this noise in Feb 2016 the day I drove home from Kerbeck, it didn't get traction with any real responses until BJONES started this thread a few months later.

I ended up getting a Chevy Customer Service ticket # in May and took it to my local dealership ( not selling one). I had filled them in on all the comments about this issue from me and others on this thread. The service advisor wrote it all up..... I told him of several other guys getting all sort of parts thrown at their cars, without any success. I told him, I did NOT want to agree to leaving it with an open ended, "do anything you want" approach. He told me once I leave it, and they call GM Tech Support for direction, that they will keep it and do what they are instructed to do by GM.... I told him, I wanted to know what that is, BEFORE agreeing to tearing our car apart. He couldn't agree to that, so I told him that I would sit on the sidelines for awhile until something is figured out by GM. I got in the car and drove back home..... that was late May, 2016. Service advisor was cool with that, and said he would keep the ticket open.

As it turned out, I sat until September, 2016 when GM Engineering sent an Engineer here to my local dealership to collect data for 2 days with some sophisticated sound analyzers. He assured me that they would not change out ANY parts, just make sound analysis. They had pre ordered 2 new Z06 rear axles for the car that were sitting at the dealer, but didn't get installed, as he knew it wouldn't help.

The next morning after meeting with them, it was decided that GM Engineering would buy back our car as they wanted it back in Detroit to use for root cause analysis. The Engineer I met with who worked on it for 2 days had already spent 2 weeks analyzing my YouTube video/ audio that was sent to Mary Barra the CEO of GM...... he shared some of the analysis data with me.

Gunrun

Can I have your old vin number? Maybe they can look it up to educate them. I will leave the car in Monday and tell them before you do any work to call me. I think I am wasting my time. Although the warble noise does not bother me too much since I pulled fuse 42 and it drones. I am concerned about long term.

Strake

I agree, I would suggest you put back in fuse #42...

You can certainly tell GM Tech Support to pull up my car..... It went back to Detroit Proving Grounds in Mid November to be torn apart to get to the bottom of what is causing this sound.

The VIN # from my previous 2016 Stingray A8 is: 1G1YD2D73G5115594

Tell them to talk to the "Corvette Brand Quality Manager". I would specifically tell them, or ask them what about the "RING and PINION" in the differential. It is my understanding that it is the root cause issue...... built not to spec..... but let THEM verify that, don't go by what I've heard.

Hope this helps....

Richard

darinvedwards

I have been in contact with the "Executive Liason" from Detroit twice this week. I have also spoken with my service manager twice via email. The parts are scheduled to arrive on Monday the 13th, and I will bring the car in to my dealer on Tuesday the 14th. The technical resource from GM sent my dealership the required parts on the 6th. I'm hopeful that the differential is the 'new' design, but everything about this interaction has been handled like a Mission Impossible movie. It feels a lot like Highplains's experience. When I ask for the part numbers, the dealership says they were sent the parts. When I ask the dealer when the parts would arrive, I get a call from the "Executive Liason" an hour later saying next Monday. At this point, I really cringe when I drive the car so I am thankful that I have some hope it may get fixed. Worse case scenario, this is try number 1 of 3 and they will be buying it back. I've kept meticulous records so far based on the suggestions of BJones, Highplains, and Strake.

walleyejack

good luck, hope the problem is resolved.

Gunrun

How did you get them to order a new diff Darin?

darinvedwards

Gunrun I don't really know how to answer that question. My dealer had requested I make a video and send to him for him to forward to GM tech services as a result of calling them and being told that there wasn't any documented issue with the car.


I was pretty mad about that and did make the 4 videos that I put on here. One it is very loud. I also posted them on YouTube also. When I replied with the videos, I copied the GM executive team (on a Saturday). I get a call Monday morning from my dealership saying an engineer from GM had called the service manager and informed him they would be sending parts to install.


I'm not sure if they are the 'old' parts or the 'new' parts, but I'm just thankful that I have some hope to grasp on to here. I have a lawyer friend who says follow the procedure of the 3 visits and document each carefully. If it doesn't work out, I will be following the lemon law procedure.

Gunrun

Who's your contact? Mine is Wendy.

Ed Ramberger

My contact in the executive office was Quentin. That was an exercise in futility.

bjones7131

My liaison would call about every two weeks and i would end up updating her. I knew more than her as to what was going on. She was very nice and polite but never added any value to my case, disappointing.

StealthStingray

Hi Fellas,


I wrote an email to the execs at GM on Sunday 2/5 and they hooked me up with an Executive Liaison. I gave her the run down this week, and she set up an appointment for me this morning 2/10 with the Master Tech at my dealership to inspect the car and replicate the sound.


We went for a 20-30 minute drive and I was able to replicate the sound many times. He acknowledged he could hear it and agreed that the differential could be one possibility as it was coming from the rear.


I asked if he had heard about this from anyone else and he said he had not.


Like others I expressed my anxiety about throwing big parts at the car considering my car is only 4 months old and he empathized.


He gave me some peace of mind by suggesting:
A. this won't effect the performance of the car
B. this won't effect the safety of the car
C. this is a drivetrain issue so if it gets worse, I am covered for 5 yrs/60k miles


and the main point...

D. He has a monthly meeting next Thursday 2/16 where the Master Techs in Houston meet with GM Engineers to discuss current issues. He assured me he would raise the topic in the meeting to see if they knew about it and if there was a fix.


I did mention our hypotheses throughout this thread about the differential and the ring and pinions, so I am hoping for a positive update by this time next week.


My appointment was followed by a call from my Executive Liaison, who seemed surprised I left with my car and that I hadn't left it with them. She asked if I was able to replicate the sound for the Master Tech, and I said that I had. She said she would call them for an update and would continue to do so next week.


We'll see! I'll keep you all posted about my experience in Houston!


Have a great weekend Warblers! I'm going to Warble to the movies later.

Highplains

If I were you, I would simply go through the procedure outlined in the post from customer service. This was set-up by the GM Corvette Quality Control Manager who took my new diff right off the assembly line and sent it to my dealer. It is specifically for those people who have the warble to use to get a new diff before the TSB comes out. The warble is caused by a faulty ring and pinion and yes, it will get worse. It is no longer a hypothesis. The GM field engineer who wired-up my car for sound and tested it said that it had gotten to the point that the warble was occurring all the time and not just at 1500 RPM. I was not allowed back in the shop but both he and the service manager said that when they took off the access plate (Detroit would let them disassemble the diff) that abnormal wear was quite obvious and the oil was silver colored from metal dust.

tcinla

I just got my oil changed yesterday and the engine is running very "smoothly" which allowed me to hear the other sounds much more prominently. I can even feel it (vibration) in my seat bottom.

I,m Sure a lot of us are just waiting for 'critical mass' to be achieved and a TSB opened before doing anything. I'm going to get the case open and see what happens.

Gunrun

I do not think a tsb will happen.

bjones7131

If you guys don't complain to whomever will listen you will never reach critical mass. Don't sit on the sidelines and wait for others to push the rope. Trust me if enough complain and threaten lemon law they will act. I suspect a lot of R/D goes into creating a TSB, GM will make sure they have nailed whatever the cause is and prob. have replacement components lined up before taking the plunge. Just my opinion

walleyejack

I mentined this before sometime ago in the thread, can t remebr when, i m old, doed this just appear to be a diff issue with the A8 transmission ? I have been following along, but am sure i missed some posts.

bjones7131

Seems to be just the BASE Stingray, and all so far are A8. They think it is the ring and pinion in the differential. Highplains had his changed out with a new improved, not new stock, diff and so far so good. Others are awaiting on the new improved diff but don't seem to be readily available at this point and time.

walleyejack

Ok thank you.
I cant get a handle on why autos only are having the issue. Different gearing tan the m7 possibly ?
I have m7 and i hear a growling more than a warble from the rear, only when first thing in am or cold start after sitting for hours. Snowed in, so can t get it out to observe rpm s this is happenning, but low for sure.

Highplains

I've been waiting for someone to try the procedure outlined in the Customer Service post. Admittedly, most of us have been pretty well burned by CS but what is there to lose if you don't want to wait for the TSB?

By the way, Bruce. They don't just change the ring and pinion. It's a whole new diff with a new ring and pinion whose design was corrected by the supplier.

IBuyGuyToys

I pm'd him last night.
Told him I had 2 cases closed on me and provided the info requested.

FYI:
First case opened in Oct. 2016 had two different customer care folks work on it.
Couldn't get any updates out of first one.

The second Rep. Sent me to another dealer and didn't hear any response from him after that.
Asked for updates both phone and email.

Second case was opened on 2/7/17 when I found out the first case had been closed and was called back by Rep. a day later saying she had to close the case (At least she got back to me).

She said the TAC (technical assistance center) said this is a "NORMAL NOISE" and the TAC is above them.

My dealer worked with TAC back in Oct. 2016 when they had my car for three days.

The service invoice I received shows that they heard the noise, couldn't find where it came from, and couldn't reproduce it in another similarly equipped vette.

I believe the big problem is that they close these invoices NO TROUBLE FOUND, rather than TROUBLE NOTFOUND.