picked up my car 5/27/23, only 2050 miles so far, no issues at all............wish I could say the same for club and forum members. Some transmissions die with 90 miles on the car, some 1000 miles, some 7500, some 20,000 but many many transmissions die.

In my opinion, having owned C4 and C5's (heavily moddified) and having C2 and C3 in the family I would say this transmission deisgn is very poor. It is definitly too weak for the modification many of us want for our car.

The 2024 design seems no better than the 2023 with many cars being sent to michigan and many more headed to the dealership with new design bad transmissions.

I havent heard GM really truly discuss the issue.

I think this transmission needs a new transmission design, I want more strength, I want valve bodies that dont clog so easily, I want clutches that hold, I dont want leaking pans and cases
Tremec has build some great transmissions, how about the 6 speed many of us had in our Challengers and Vipers...........I abused the hell out of that thing, never and issue.
I feel like this can be done.

Do you trust that your transmission will last a cars lifetime, 100,000 miles? more?

I do not

 

Well Said. I believe your statements are correct.

 

so are you keeping your C8?

 

I know GM has had some problems with the DCT - how many are affected I do not know. But for those that have had issues, it sure can ruin what should have been a great car ownership experience. In the C8’s fifth model year, one would hope that this would be a thing of the past.

 

Hey atleast its not a 4l60e...

 

So genius, why did you buy the car.

The transmission issue is unfortunate, but it is way overblown. All high-performance car brands have some model specific issues, from Ferrari to BMW to Porshe.

No car company designs their cars to be modified. If that's what you want, then go to the aftermarket for purpose designed race components. I don't think you will find any with a 5-year warranty.

 

Most likely there are some inherent design issues that we are not aware of. I don't think more power would worsen the issues or that less power through it would fix them. It has nothing to do with being a 'performance' car and more to do with dcts being very complex and finicky. It's the nature of the beast. GM would have been better served having had a manual as an alternative tranny.

 

I think it's a bit over blown myself. I also think many of these failures are due to improper use during brake in. You see people flogging these cars right off the dealers lot and this is just asking for trouble.

 

The problem is a manufacturing process control problem, not a design problem. It is the luck of the draw. If it was a design problem the failures would be the same and occur at a higher rate.

Most of the failures happen early on. So far, my DCT has been fine but I only have about 12K miles on my car. I plan on keeping the car for a long time and purchased a Platinum Protection plan that will cover the DCT for nearly 10 years total between it and the powertrain warranty. If it makes it 10 years then I'll assume it will likely be good for longer but I'll monitor the problems during that time. At least by that time if there is an inherent design problem then options will likely be available.

Strength isn't an issue in the stock configuration. Many people track the cars and don't brake DCT components. I don't think I've seen one post from someone that actually structurally broke a DCT component in stock configuration. The closest I've seen is a broken half shaft.
The clutches hold unless HP is significantly increased and if you want to add a lot of HP then you need to expect to make drivetrain modifications also. I suspect there will be options when the ZR1/Zora versions are released.

There isn't evidence that once the DCT has had it's 7500 mile DCT filter change (and the car was maintained per the schedule) that the valve body failures are related to contamination. It is quite possible there are other things going on.

The pan and casting leaks are a process control problem since many C8s don't have the problem.

 

Overblown.

 

I owned a Honda Africa Twin motorcycle with a dct transmission. Never one issue with it. Yes it had its own extra filter to change. No big deal really. Have a friend who’s had 3 Honda DCT bikes and no issues ever. DCT is not rocket science new stuff. Tremac should not be having issues at all as long as these things have been out.

 

you know I am really torn, my C5 was much more fun, 735hp, 6 speed, REALLY fast, brutal speed with tires breaking loose with all nannies on while accelerating, coming upglued at 70,80,100, it was just fantastic. Car cost about 35K to buy and build
I have contemplated going back to a C5 or more likely a C6 and building the LS

Im not kidding everytime I uncover the C8 and start it to leave the garage I expect a problem. Update failiure, dead battery from failure, tranny related failure or the worst, those cheap *** powder rods letting loose and killing my engine

 

well genius I didnt realize my 2023 would have the same transmission problems the 2020 had...............generally dont car companies step in and get a redesign or fix done??

chevy has provided me with a transmission with which I could modify my car and survive for decades, M21 in my 70SS Chevelle, Turbo 400 in my 68 Elcamino SS, turbo 350 in my 74 Z28, the trans in my 2011 and 2013 Camaro's, my C4 trans was ok, my C5 6 speed took 735 HP with no issues.............I expect the performance car I purchase to be able to take some reasonable modification...................no 1000 hp I understand, but come on, this tranny wont hold up to 600

and when modifiying I dont expect a warranty, not worried about that

 

I hope youre right RapidHTC..........I am just seeing so many go down, I think the percentage is higher than we first imagined

 

I thought this was going to be a Santa thread 🎅🏼

 

A majority of people are happy (mostly) with the car the way it comes from the factory. Making a car's drivetrain more robust than necessary costs money. I don't want to subsidize people that want to modify their cars when I'm not planning to modify my car.

 

Agreeing that there shouldn’t be problems with the DCT or anything else power train related what documented percentage of failures do you have year by year in C8 production?

I am fortunate, as I believe most are, in that my 2020 has been a zero defect car so far. Regardless, I picked up GMEPP Platinum for an additional seven years because I plan on keeping the car and if there is a power train problem I believe the plan is good insurance.

 

I have not seen any issues posted here...

 

My 24 SR was properly broken in, no RPMs over 4k for the first 500 miles. Not pushing it much over 4k since. And at 930 miles, my valve body failed. It was nothing I did, it's the design of the DCT. Now I have a new valve body, filter and 11 new Qts of fluid in there & 1250 miles total. So far, so good.

 

hope she gives you know more trouble!

its an awesome car, fantastic design, a real bargain, I just wish GM would come up with a new trans or trans fix for us all