All the responses to the thread about transmissions is greatly appreciated. I am not a mechanic or engineer, but it would seem to me that “if” just 2% or 3% of the 120,000 plus owners of C-8 corvettes may have had issues with their Vette’s transmission than it should be talked about. There are only a few websites such as the Corvette Forum that have so many subscribers who are or have been engineers, corvette technicians, GM employees, and race track enthusiasts, to just guys like me who have a love for American sports cars. If it’s just 2% of the more than 120,000 C8 owners that have had transmission issues that is 2,400 owners. Hopefully, and more than likely, the figure is less than 2% of the owners that have had transmission issues of some sort. Well that adds up to a lot of dollars for a car manufacturer and/or transmission manufacturer to have to pay out for repair/replacement under warranty. That is why I genuinely like to read the forum, not just to hear about the issues members are having with their Vette, but I enjoy learning about the various models, accessories, “How To’s, etc. Keep in mind, it is rare that any current GM official is going to tell you there is a significant mechanical issue with a current model car. If he or she does, they more than likely are soon to be a former GM official. We have to rely on the honesty of GM to provide recalls when there are issues with our cars. Overall GM makes an excellent car and let’s hope that continues into the future. Just my thoughts.

 

Just picked up my new 2024 C8 after a
16 month wait. Drive it home and wasn't happy with shifting and making a
noise in reverse. Turned around and
brought it back to dealership. Needs a
new transmission......say what?
3-4 week wait they say. I was also told
it would be the newer updated version.
1st loan payment due before ever driving the vehicle.

 

What was your VIN... and did they say you got the older transmission or the newer one with an issue? I ask because I have a 2024 with a low VIN and curious if some of the older transmissions made their way into the 2024s. Was told that you no longer need the extra fluid in the newer transmissions so I assumed they were all swapped out.

 

Unless there is another yet unknown change to the transmission all 2024s already have the newer transmission.

 

With one post on the CF from Petro, I'm going to take the news with a grain of salt. I have no reason to believe the older style transmission is in my car but it doesn't hurt to follow up. Even if he has the newer style and it blew up, still worth asking the question.

 

This was the question:

The answer is no it was not changed to overcome alleged "mechanical issues", not unless there was another re-design after the one introduced in late 2023, that is in all 2024 models. Attached is clip from a Sept 2023 article that indicates the redesign is a "new case" (and it is a new case with a different bolt pattern for the what is also a new sump design - see second clip). The mods are "unrelated to functionality or durability...". Changes indicated are a "revised cooling system" and there is no longer a need to add additional fluid for tracking (not it does not say it has the additional fluid - the redesign makes it unnecessary to add additional fluid).

The second clip shows the the bolt pattern changes that may be used to identify the transmission that you have.

Here is a link to the tech link article that discusses the bolt pattern. That article also indicates the change was introduced in late 2023. Someone on the forum can provide the exact vin number for the change.

https://gm-techlink.com/?p=17970

 

Sorry to hear, could be wrong, but this may be the first 2024 we've heard with major issues.

 

As per GM 2 quarts not needed for Homestead or Sebring as there road course and track don't have much elevation changes that cause the need for the 2 quarts especially dropping cork screw turns

 

Yes, that's what they told me. The remaining 2023 tranny's were used before switching over to the 2024 updated one. Who knows if it's even true?

 

Not disputing the fact that you were told this. But all indications are that the switch to the new Die 3 design was made in 2023 model year late. See post 26 which includes two sources (one a direct GM source) that seems to say it was changed in 2023, late. Also, I dont think they refer to them (the transmissions) as 2023 and 2024 versions - they are just different designs. Anything is possible - so I guess one might find an older Die 2 design in a 2024, but its not what GM said they were doing.

 

It's true there was a post showing the newly thinned pan as well

 

Sure hope that the transmission problems that some are experiencing have been resolved - not a good PR image if it has not been fixed, even if it is a relatively low number of cases.

 

My C8 is at the dealership changing the transmission assembly, due to failure in the actuator, whatever that thing is, is it the same thing people talkin here in terms of C8 Transmission issue here ?
I had the same issue because of this, the care won’t start up and change gear

 

Not enough information, I think. The transmission had tons of "actuators". Examples are electronic limited slip differential(eLSD) actuator, Transmission Park Valve Lock Solenoid Actuator, multiple Transmission Control Solenoid Valve solenoid actuators. One might think that if it is a solenoid actuator in one of the two valve bodies, it might be resolved by replacing the valve body. When an entire transmission is replaced (based on the Service Manual and also forum reports) it is usually because valve body replacement did not solve the problem. And in those cases, generally no one ever finds out what the problem actually was. I suspect that the dealers do not know, and GM may or may not find out later - depending on what they do with defective transmissions when they come back.

 

I'm considering buying a used C8 2023 Sting Ray w/ Z51, & the carfax mtc record shows a trans fluid chg on th 15th of a month, then again on the 30th.

So, I've read this entire thread. The cars $85k, but I would have plenty of warranty left.

Talking about bad PR...I'm now thinking about not buying a C8 and sticking w/ Porsche 911's. I've had 2 of the w/o any issues.

 

I've had a 2020 C8 Since January 2020 Z51 tracked 4 times Launch control at least 140 knock wood no issues. All new cars have some with issues. GM recently rated 5th in customer satisfaction and reliability compared to Mercedes, Porche, etc. dead last was Land Rover

 

Still waiting on a new transmission for my 2024 C8 Corvette since 10/28. Pulled out of the dealership and brought it right back to them.

 

We can’t all be so lucky haha. I never even launch controlled my C8 once, and I may never get a chance to since it may be back at the dealership for the last time. I wish I had done it at least once now. I guess I killed my transmissions with kindness.

 

You DO realize Porsche has plenty of issues as well, right, despite your anecdotal experience? No manufacturer is perfect.

"Porsche Shamed As Least Reliable Brand" https://www.carscoops.com/2022/12/po...box=1671887240

https://www.roadandtrack.com/news/a4...ails-on-track/

Also don't forget the IMS bearing issues that effected an entire generation of 911 and Boxster cars (even the base models), and even the ones that didn't grenade their motors left their owners with the concern looming over their heads. Then we have 911 cylinder scoring issues (https://rennlist.com/forums/997-foru...e-failure.html), GT3 engine failures, GT4 cracked strut towers, water inside headlights and taillights of the latest GT3, etc.

 

Check if it was a transmission filter or actually a complete transmission flush?

2 in short period of time makes me think they were getting CEL codes they were trying to clear.

yes u will have a good warranty remaining