General Motors filed paperwork with the National Highway Traffic Safety Administration to launch an investigation into reported problems with the eight-speed dual-clutch transmission found in the C8 Corvette Stingray.
Some C8 Corvette Stingray owners have experienced gasket failures with their vehicle’s Tremec TR-9080 transmission, resulting in leaks, while others have observed error messages telling them to put the vehicle in park and take it in for servicing. Paperwork filed previously with the NHTSA indicates some problems could be traced back to “debris on the park position sensor magnet causing an incorrect position reading to the (transmission control module).”
After widespread complaints to GM and online, the automaker decided to launch an official investigation into the matter to see what’s really going on. The automaker sent out a letter to dealerships requesting technicians remove the transmission fluid filter when a 2020 or 2021 model-year Corvette comes in for its first scheduled maintenance at 7,500 miles. Technicians are instructed to carefully remove the filter, place it into a plastic bag without letting the fluid drain out of it and mark it with the associated vehicle’s mileage and VIN. The filters will then be returned to the warranty parts center and later inspected by GM engineers.
A poster on Corvetteforum.com previously shared communication from GM that indicated the transmission pan and gasket had been redesigned at some point during the 2021 model year. The older pan design, according to the poster, was made of steel and was connected via two studs and 13 bolts, whereas the new pan is cast aluminum and features 17 bolts. The new pan also does away with two reinforcement plates used in the original design and has a new machined groove at its leading edge to help properly seat the gasket.
GM Authority will provide an update on the C8 Corvette transmission investigation once more info becomes available. As we exclusively reported earlier this month, production of the Corvette’s eight-speed transmission will begin at GM’s St. Catharines plant in Ontario in the second quarter of 2022.
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Comments
Is it me or is GM having lots of issues? This issue, the issue with lifters on V8’s. I believe they have had past transmission issues with the Colorados and Silverado 1500’s. Oh ya, can’t forget the Bolt fiasco. It’s really sad. The prices are going up and the quality is getting worst.
Was thinking the same thing. Easy to see why they want to convert to EV’s. It appears they have hit the glass ceiling on engineering ability to make reliable cars and trucks. With EV’s there are fewer moving parts and the margins will be much higher. Unfortunately a massive amount of good people will become unemployed.
That is nonsense it has nothing to do with electric cars or people losing their jobs
GM hasn’t hit the glass ceiling they are just watching things much closer
and addressing the problems. The C8 Corvette is a complicated machine
and there is going to e bugs to work out.
What a horribly lame excuse. They should work the bugs out of their complicated machine before they start selling them.
My 2024 Z06 with only 300 miles just went in for a transmission oil leak, what a mess!
Yes they got a bad batch of valve springs from the supplier and several of their models had a failure in the valve train. As a member of a C8 forum, there doesn’t seem to be lot of leak issues, but some. And there have been reports on the forum about the transmission parking position in the . Overall the serious problems have been few. I think GM is probably trying to get ahead of the issues with this NTSB paperwork. I’ve had no issues with leaks or parking position on my car
Maybe, just maybe, it has something to do with the layoff of thousands of engineers when GM was downsizing direct labor at the beginning of the last non-COVID recession. There has to be a downside of laying off so much inside talent, and relying on suppliers to be the watchman for their own parts and sub-assemblies. That’s like believing thousands of engineers sat around and did nothing.
That’s what happens when engineers are replaced with bean counters. One need look no further than The Boeing Co. Unfortunately, the mantra in corporate America is short term profits over long term customer satisfaction (Toyota, Honda)
You apparently don’t know that the DCT was designed by Tremec, not by GM? So GM layoffs had nothing to do with any transmission issues. But why worry about facts when its so much easier to spread your bias. FWIW, with 5800 miles, my ’21 C8 has been perfect.
Ah, I just turned 7,249 miles on my 2021 C8. Took the car in for the scheduled maintenance and was informed that my transmission is leaking! Now the car will be sitting at the dealers waiting at least 2 weeks for a new transmission!
Ugghh. Sorry to hear that. The 2-week wait is definitely frustrating, but if it were me, I’d be more annoyed at having to drop the engine out of a nearly brand new car. Hope it works out.
Did they give you the ETA for the new transmission? I just received confirmation that the dealer is ordering one for my C8.
Same here. 2021 with less than 2400 miles. Had check engine light early on that was reset by dealer with something unexplained about the transmission. 3 weeks ago another check engine light and the car has been at the dealer since. Between GM and the Dealer it’s been a real clown show. Just goes to show, regardless of how much you pay, it still a Chevy.
No more than normal and not the most we have seen from the manufactures.
A lot of issues never make the news. Nothing shady going on nor are they hiding anything. Recalls go out ALL the time for components that could make the car more unsafe than this issue.
I had a car back in 2000 with a mass recall for a steering box nut. Apparently it could back itself out resulting in the inability to turn right. Yea. I like turning right. I do it all the time.. LOL
GM JUNK Problems after Problems. You pay soo much for one of these Vehicles and then the problems begin.
NOW “gm” is opening an investigation? The dct has been out for three model years and “gm” has known about problems with the Tremec transmission from before the release of production cars. Another reason for the “official” investigation might be that the NHTSA found out due to direct customer complaints to the federal agency.
No leaks with my C-8 also best car I have ever owned but I walk past it for my 2019 SCS AT4 GMC Sierra most mornings.
I hate when people say “best car I ever owned” when speaking about a new car.
Let us know in 10 years.
I understand your thoughts, but automobiles are not designed for the second or third owner in mind. They would be completely unaffordable if they were engines for 200k miles. Everyone should understand buying a pre owned car is at their own risk. Huge aftermarket to provide extended warranty, but the cars are designed to be as flawless as possible for the original owner and warranty period.
I have a 08 GMC Siara . That truck has 112,000 miles on it .The only thing I’ve ever had to do to this truck is put brakes and tires and change the oil on it. I just did the first tuneup at 105,000 miles the truck still looks like brand new. Now I can say that’s the best truck I’ve ever owned. I have a 2021C83LT loaded that cost $105,000 I have had no problems yet I have a little over 12,000 miles on that car I love this car. I have always said don’t love something that can’t love you back but I do really love this car it’s great.
I have a 2016 ss camaro and a 2017 zr2 colorado and both had transmisson prolems.
And neither has a dct so what is the moral ? That GM can’t built reliable cars then go buy yourself a Bmr or a porsche my son just got rid of his M4 htc because of all the problems he had from having to replace the whole differential (13 k’s) to paying $3500.0 for a bumper cover
Well he went back to his Lexus
Me I am a C8 guy waited too long and paid too much but O love it so far. ✈️
Interesting comment. Wife has a 2019 X4 and the pinion bearing went bad. Is covered under warranty but the service guy tells me they will have to find a differential somewhere. I asked him why they just don;t replace the bearing and he said BMW does not allow them to do that so they MUST replace the entire differential. Looked on line and those things are $4,000 for just the differential. Got to believe labor would be at least $1,000. I am on my 5th Denali XL and the last one went 180k miles with regular Maintenance and had to replace a torque converter for at 102k miles for $2,000, not bad. Love GM products but they seem to be having some problems as of late.
My Cadillac had a rear end go bad, and the service advisor said GM required the whole rear end be replaced as a unit. The replacement arrived in two days under warranty. Word around town is the dealerships don’t have mechanics who are proficient enough to dive into engines, transmissions and rear ends. They call them code readers. Hope that isn’t the case.
Unfortunately “code reading” is what the skill has become. It’s sad but a good mechanic seems to be becoming a lost art nowadays.
get a manual trans, no problems
How about taking care of owners of C7s with less than 15,000 miles on them, with horrible transmissions that shutter? Out of warranty by time but not mileage. Bad business and customer service.
2016 Denali 6.2 with 8 speed trans…..shutter and shake just before warranty expired….replace fluid with new moble1 II fluid
at dealer with CORRECT amount after flushing trans 2 times…fixed it…..but why don’t GM recall for the fix?
Leaves bad feeling about trusting them.
I had a 2015 Denali XL and had the same problem. Ended up being the torque converter. Happened at 102k miles so had to pay $2,000 but that was the only major bill after 180k miles when. I traded it in. Not bad.
GM , TALK TO ZF IN GERMANY AND HAVE A TRANS MADE IF YOUR HAVING SOOOO MUCH TROUBLE WITH THE CORVETTE TRANS.
Opinions are that OPINIONS
Fact I have owned 5 Suburbans, and 10 CorvettesI. Have yet to experience any real issues with any of the vehicles, yes there have been a few, but not anything that cannot be addressed and repaired. Seriously, an oil seal going bad and leaking is not a reason to condemn a vehicle or manufacturer, it is just a seal, an inner valve spring or a faulty switch. Get it fixed and move on! Why all the negativity ????? It’s not a perfect world.
GM SHOULD CHANGE THEIR NAME TO HOOK AND CROOK.
This transmission is currently produced by Tremec. GM is bringing production in house to resolve supplier issues.
Guess I’ve been one of the lucky ones so far. I have 6,000 miles on my ’21 3LT Z51 with no problems to speak of – especially transmission. Hope it stays that way [knocking wood]
My 2021 C8 delivered in March (built in Feb) has 7700 miles, serviced by me only. No complaints.
GM has produced a fantastic car, with many new features. Yes, cars have problems. But as long as they are
not ignored and fixed I am okay with that. I’ve owned a lot of cars. I love this new Corvette.
CEO Mary Barra will get to the bottom of it as she did with the Killer Ignitions…
In Ten Years, and after another $25 Million Dollar bonus, after denying there were any “Confirmed” defects.
This GM tranny problem is getting old. Colorado’s, Silverado’s transmission (shudder) /(slip) issues’s.C7 (auto) Corvette’s
same thing! (shudder)/ (slip). Now the C8 Corvette. I can attest to these problems. My 2019 Colorado had the issue, and my C7 auto is in the shop now for the same issue. Thank the extended warranty gods, as the cost to replace the trans fluid with the so called right stuff is $700 plus if it’s out of warranty. GONNA TAP THE BRAKES on anything from GM for long time. The out of pocket $$$$$ after purchase is way to high.
Except for the fact that GM didn’t design or build his transmission, you might be on to something. But, sadly, you’re not.
Stop
I have bought 10 vehicles this century: 5 GM and 5 non GM. 4 of 5 GMs have had engine issues (exception DMAX). 0 for 5 on engine problems on non GM. At best I can chaulk the 5.3 and 3.6 as being old GM going bankrupt GM as root cause. Skittish to buy another GM
I’ve bought 2 Corvettes this century. Zero problems with either.
Give it a rest Dude. This isn’t the place for political crap.
On another note: now all us C8 owners need to take a look at the pan on our Transmission – is it cast ?
My transmission has a date stamp of Jun 2021 on it.
What is better than a C8 corvette …. 2 C8’s !!!
What is better than 2 C8’s in the garage ??? if one of them is a Z06 !
One dealer was pretty honest saying they might get 2 Z06 in one year, and they had 15 names on a list.
They offered to ad my name jus tin case.
The dealer that sold me my C8 will not take my deposit until more Z06 info comes out.
Kerbeck will take take any more deposits, the list is full.
Then there is another dealer on the East Coast, has over 5,000 deposits. Can they possibly deliver ? I doubt it.
What does this have to do with the article ? – Nothing, but at least it is about Corvettes.
Good Info IMHO
At car shows there are a lot of Street Rods and old and newer muscle cars that have Supercharged big block Nitrious Oxide engines in them with an aftermarket Tremec transmission. I have never had any of those guys complain to me about having a bad Tremec Transmission. And a lot of these guys with the modified muscle cars drag race them hard. Then GM does things their way and whamo, problems with this Tremec transmission.
You do know this was reported a couple of months ago, right? You must know, since you copied that other report almost word for word.
Ive owned a 17 Camaro and had to let it go when transmission started to have problems, I’ve regretted no taking a manual one.
keeping fingers crossed ….6,200 miles and zero problems
Seven year old Cayman with PDK (Doppelkupplung) transmission, with zero issues. And it is not a garage queen except when there is salt on the road here in northern Ohio. Yes I drive it in the rain. Before the Corvette crowd strangles me, yes I had a Corvette one time. I had to change out the tranny, and then the engine both out of warranty. I also think that I didn’t learn my lesson as for my work car I own a 2019 Chevrolet Bolt with the Korean battery. But you know something? It is better than my Corvette was.
It’s my first time ever owning a GM product and I chose the C8 Corvette. My check engine light came on Tuesday and took the car in immediately. I got a call back to come pick up my car on Friday. Yes, it took 3 days for them to look at it. The news was not very good. I was told that an internal selenoid was sticking due to debris. Unsettling but I guess it is what it is. I was told that if the check engine light came on again, I would have to drop off the car again and that, a minimum, it would take one month to get it back. And here is the kicker, they don’t have loner car to give me in the mean time. 😒. This is my only car, so that means I would have to provide my own vehicle while they figure out what is wrong with my car. And yes, I had to rent a car to go to work while they had the car for 3 days. I love the car but now I’m scared to drive the thing for fear that it would leave me stranded in the middle of a busy highway. I hope GM keeps an eye at this forums and take note at what kind of service their customers are getting.
I would escalate the loaner with GM. GM used to determine loaner by the price of vehicle you bought and not the make. My diesel truck used to get me an Suburban or Escalade rental at Enterprise while guy with a Malibu behind me got zippo.
Escalate all you want, but all the dealers around here sold off all the loaners a long time ago.
“We don’t do that at all anymore. It’s not a thing.”
That’s what I was told just last month.
Loaners can include rental cars as well just not dealer loaners. Also in tight supply depending on your locale. They may give you something else of value as you are buying a high profile and expensive model. Never know until you call
does your c8 have a newer cast aluminum trans pan? i need to check mine
I have this problem with my 2020 c8 Corvette. The mechanics do not want to take care of my car since the problem happens randomly and I need to disconnect the battery to restart the car, and the code is then deleted. Does anyone have a suggestion?
In the following order:
I would speak with the service department manager at your dealership. I that doesn’t get attention I would then speak directly with the GM of the dealership. If you still do not have anyone’s attention – contact Chevrolet Customer Assistance at the phone numbers shown on P. 304 of your owners manual. I am told they can be quite responsive and influential. If none of that provides results – contact Harlan Charles at Chevrolet Corporate. Good Luck
MY C7 HAD THE TRANS SHUDDER PROBLEM STARTING AT ABOUT 33,000 MILES. I’M THE ORIGINAL OWNER.
THE DEALER [KERBECK] SERVICE DEPARTMENT SAID WAS NO LONGER UNDER WARRANTY [ IT WAS ]. A LETTER TO MARY BARRA GOT RESULTS.
CIOCCA CHEVY DID THE TSB SERVICE. NOW RUNS GREAT. 52,000+.
BUT, SHOULDN’T HAVE HAD TO GO THROUGH ALL THIS TO GET IT FIXED.
Sure its a Tremec trans. Maybe GM should have done more testing before using it in production. Well after 5 tows and now the 3rd dealer visit. They should get it right this time.
Andrew S.
I have a 2018 GMC Denali 2500HD 6.6 Deisel a 2015 Camaro ZL1 and 1973 Covette. These are great vehicles. My 2500 HD pulls all of my trailers loaded with ease. My ZL1 is the fastest and the most fun car I have ever owned. No issues with any of them. I hope someday to add a C8 to my collection.