the Z06 doesn’t have a supercharged engine and uses basically the same trans. The ZR1 is supercharged and the engine and trans are both beefed up for that car but we’ll see what dealers actually charge and what production looks like when it starts next month.

 

I've been here plenty and I've read all the stories. I can also do math. The failure ratio is not as high as people think. They have built more c8's than any other generation of vette. Do the math.

 

So, with your math what percentage did you get?

 

How do you know the failure ratio is not as high? Do you have access to GM’s internal data? There’s probably a lot more transmission failures out there than we know of since a majority of C8 owners are not members of this forum. I’m aware of at least seven C8s that have required valve body replacment including my own.

The fact that the OP has had to go through TWO BUYBACKS in two months because of transmission failure is unacceptable. The transmission failed after two days of ownership with his first C8.

C8 owners need to get their heads out of the sand. The Tremec DCT has reliability issues. Plain and simple.

 

He did the math. He knows. Now I want to know what he came up with.

 

What a crazy thread. After all of the panic attacks and issues with the first two cars at one point OP was still considering a Z06. Everyone is a test pilot for new vehicles these days. The demands and the bar for technology and performance has never been higher and automakers cannot keep up. Add in the fact that the mandates for ever higher fuel economy and the technologies needed to achieve this is a recipe for over engineered cars with far too many microprocessors, sensors feeding them data and far too many lines of software attempting to make it all work perfectly every time you turn the key.

The C8 is no exception. Most advanced and highest performing Corvette ever produced in these volumes. GM has a problem with the DCT but I am convinced it has everything to do with Tremec quality control. The failures not being related to anything specific and the fact a ton seem to happen so early on in the cars life it has to be the myriad of sensors and parts within the DCT that are causing the error and eventually the need to replace them. On the flip side you have tens of thousands of cars that just go. This is a QC problem that seems hard for me to believe has not been resolved yet.

 

Like JDSKY states, is highly likely on the Tremec side and then it is likely on their component vendor side and if they are like many companies working to shave costs and time, are allowing their component vendors the luxury of handling shipment level QC instead of either a 100% or some random percentage check AT Tremec on INBOUND side - been there done that at. company and was shocked we were not keeping our vendors honest - cost us quality AND customers - sound familiar here?

 

The ZR1 is turbo charged, not supercharged.

 

Less than 0.5%

 

I hope you're correct!

 

I’ve had two DCT’s fail on two brand new C8’s. I’ve spoken with people I cannot name who have told me all the DCT’s they are fixing/replacing including a brand new Z06. I had a 2020 owner who’s had their C8 in FIVE times and had the trans replaced, and it still has issues.


It’s not 0.05%. GM is sending out letters trying to void warranties on people’s transmissions if they “didn’t do the DCT service”. And we all know GM will never release internal data showing us just how high the failure rate is.

I intended to keep my cars well past 100k miles. Tell me, is there any scenario where these DCT’s even make it to 5 years/100k miles? My first Vette couldn’t even make it 8 miles, and the other failed at 3000.

 

Over the production years of the C8 there have been several polls here, I've read them all. On one poll, about 15% of respondents stated that they had some sort of trans related issue. This could be something minor from a few drips of oil, a case pan porosity issue, a software reset, a flush of fluid or simple dealer related repair. Of the 15% about 2/3 or about 10% of respondents needed a transmission replacement. I know this is the internet, and I know the majority of C8 owners likely do not visit this forum. I also know that C8 owners with issues, trans or otherwise are more likely to visit this or other forums. It's also interesting to note another C8 mid engine forum, closed a thread quickly with just a few posts related to transmission issues.

I know of one C8 owner first hand local to me, who is the father of a son that is a concierge at a P-car dealer that gave me a ride to my shop. I mentioned to him that I was looking at C8's and he said his dad bought one and loved it. I've since learned, his dads C8 needed a trans replacement. The problem is real, and it's well known and getting more so all the time. Talking with other enthusiasts, they know too, and so do some sales people. Lots of new 2025 C8's here that are being heavily discounted, lots of unsold 2024 too. GM would have been wise to fix the issue once and for all to instill some customer confidence. Had it not been for the high potential of a trans failure, I'd have been driving a C8 years ago.

 

I'm betting GM and dealers too are subsidizing their income with the ridiculously high costs of fluids, filters and all labor for maintenance related to anything transmission related. I'm in the vehicle related service industry and what GM is charging for anything to do with the trans is McLaren or Lambo pricing. There must be a reason. Lots of cars and some motorcycles have DCT's and the service costs are a fraction of what GM charges.

 

Beyond pitiful. And, just because someone associated with GM in any way said something has or hasn't happened before may or may not have anything to do with reality. Sad. Time (past) to move on.

 

As someone who waited 4 years to purchase a C8 it’s beyond sad for me. I won’t be rolling the dice again though, not even on a Z06. More car, more money, more payment, and that DCT will blow up and I’ll be right back to where I am now. Driving a loaner for 3+ weeks and burning even more PTO.

No thanks.

 

exactly.....

 

Link to data points for your math....(Rhetorical I know where they came form...)

 

Ah yes of course, was just pointing out the Z06 is not the FI platform but the ZR1 is, thanks.

 

Does anyone know what GM does with all the buyback vehicles?

Seems like fixing them and sending to auction would be the logical move.... But what are the chances they are going straight to auction as a lemon? Now being a used car, no lemon law applies.

 

On mine it was recorded by the dealer as a "service visit" with no more details than that.