Strake

Freelance,
happy to hear you could get resolution without a huge run around as so many forum members have had. Glad my video was a good reference point for you.

i'm in total agreement with bjones7131 note above.... Strength in numbers..... get GM to get off the dime and clearly acknowledge this issue and get the word out to all of the dealerships. enough of this nonsense .....

bjones7131

Meant to say TSB, auto correct got me.

Bill Sargent

I don't get how most get a new Diff and it fixed the issue when I got both Axle Housings & bushings and it fixed mine. Maybe when replacing the diff, they also replace the bushings. According to the brand service manager for chevy, it's not the diff. At least on my 18, he was right. Got a nice letter in the mail today from GM after my final email to the CEO. I ask her to inform all dealerships and her customer service rep said the info is on their site that all dealerships can access if they will just do it. Good luck to all

123vette456

Would someone please post the e mails for who we should contact at GM?

walleyejack

glad it worked out for your Bill,
you have endured enough of their run around.

stillcrazy

I am glad your's is fixed, They repaired mine with a new rear end assembly, I can't explain it but, I don't trust G/M they have ,as you well know, used the shotgun approach to the problem. They blamed everything from soup to nuts before they came up with the axel housing and bushings.

rmorin1249

The shotgun used to repair my car was replacing the left side thingamajigs. I've only driven once since the repair and did not hear any warble. I will know more when I get out on the highway and can vary my speed to get it in the correct RPM range. I agree that GM has done a very poor job in communicating to their dealers.

bjones7131

mary.barra@gm.com GM CEO, but she will never see your email and will be handed off the an assistant, she can't read and answer all the emails she must get, but you should get a call from the assistant. Good luck

Scruff Vette

I spoke with Jeff Strausser (Corvette Quality Brand Manager) yesterday at Carlisle. A warble TBS is coming...soon. GM is well aware of the issue and has a fix based on "replacing the left side thingamajigs" mentioned above. The repair does not entail dropping the rear end, pulling the car apart etc. I may have more info later next week.

c54u

This is good news!

joemessman

^^^ Good news Indeed! I have almost 75,000 miles on the car and fortunately I have not had the issue, but this is good to know just in case. (knock on wood)

montanaman

Man I started reading this thread that started 2 years ago and it is shocking to me. As a new owner of a new 2017 C7 (7M) I don't want to have to cross my fingers every time I drive this car. I purposely stayed away from the new Mustangs due to the many problems they are having with the GT and went up a notch to get the Corvette believing that it would not have major issues ( or even many minor ones ). These cars have not changed much at all from 2014 so I would think by 2017/18 they'ed be almost bullet proof. Appears not. I know, I know all brands and cars have problems and blah blah but when it comes to brand new cars with major power train issues well there is just no excuse at this point in time. Although I made the mistake of watching a You Tube video on the cars being assembled in Bowling Green. I saw what looked to be about a 23 year old kid in a dirty t-shirt hooking up the rear bumper assembly. You won't see that in Stuttgart.

Is this "warble" issue only on A8 cars? I'd like to check this potential problem off the list and hope my car is solid. I love it so far but if things start to fail it won't be around long.

SoFloVette

stillcrazy

good to hear, however, I will wait before I get excited. There have been to many false starts, to many wrong excuses, Let's hope they finally get it right.

stillcrazy

Yes, It is found only on the base C/7 with the A/8

stillcrazy

As you read the above threads, it's not NORMAL, if push comes to shove make copies of the above threads as well some of the earlier where G/M admits there is a problem with the rear and take them to your dealer and put in their face, NICELY,

7thgeneration

Seems as though it would be a better idea to purchase a Z-51 or above to avoid issue ?

montanaman

So let me get this straight. It took GM 2 years and hundreds of customers helping them diagnose and acknowledge a problem with the A8 transmission on new cars and are just now putting out a TSB? Wow.

Freelance4ever

The C7 A8 gets a different gearing in the differential from the Z51, Z06, ZR1. When the dealer told me bad differential without having to bring up these threads, why I agreed to have the work done (for free). It coincided with what I read here, I didn't have to convince them, they convinced me. TSB coming? Good news I say. They put the exact same diff in mine that came out. No new part# or anything that would distinguish it from another bad one. Now was it coincidence that shafts and bearings are also disconnected and replaced? I dunno, no itemized list was provided but I do NOT have warble and it was bad!

joemessman

This TSB would be only for the differential warble. They still haven't addressed the torque converter issue considering that they just replace the torque converter for the shudder and shifting issues. But it does appear they may have the proper repair for the differential finally.....I hope. And sometimes the TC issue isn't even fixed by replacing the TC. Go figure.