There’s some confusion going around about proper maintenance for the 8-speed DCT automatic transmission that sends power to the wheels in the C8 Corvette. The confusion comes from a letter GM is sending to C8 owners reminding them of proper transmission maintenance.
The letter reminds the Corvette owner that the transmission fluid filter must be replaced between 7,000 and 8,000 miles, at 22,500 miles, and at every additional 22,500 miles. The transmission fluid itself needs to be changed every 45,000 miles or every three years.
The confusing part comes for owners who had their transmission oil filter replaced before 7,000 miles. GM recommends that if you’re one of these owners, you must have the filter replaced again by 8,000 miles. GM is very specific about a transmission oil filter replacement happening between 7,000 and 8,000 miles; no sooner, no later.
A Facebook user named Allan posted a photo of the letter from GM asking fellow C8 owners for clarification. The throbbing brain of the Internet assured Allan that the service intervals haven’t changed, but free service changed as of the 2024 model year. For the 2024 model year and newer Corvette models, the free initial transmission service is good for three years rather than two. Also, the free first transmission service and free first engine oil change are now separate maintenance items, so they don’t need to be performed at the same time to get both for free.
However, for those services to be performed for free at a Corvette-certified Chevy dealer, the number on the odometer has to be within the parameters of the recommended service intervals.
The transmission in question, the Tremec TR-9080 DCT, manages power for every C8 variant, including the base Stingray, the hybrid E-Ray, the track-ready Z06, and the monstrous upcoming ZR1.
This isn’t the first tweak GM has made to the free first maintenance visit(s) for the C8. In 2022, two years after the mid-engine Corvette’s debut, GM increased the time window for customers to receive reimbursement for the first service visit from 12 months to 24 months.
Comments
A Corvette’s supposed to have the engine up front and a proper manual transmission so you can row your own gears and actually drive the car, not let some computer do the work. Back in my day, Corvettes were about raw, American muscle, not this over-engineered European wannabe bull crap. A proper manual transmission never let you down, and if something went wrong, you could fix it in your garage with a wrench and some elbow grease. Now, you’ve got to call a technician just to figure out what’s wrong! The C8’s trans might impress the kids, but real drivers know it’s just another piece of over-engineered junk waiting to fail. Give me a C6 Z06 or a classic C2—those were real Corvettes, built for drivers, not computer-simulation enthusiasts.
Ron
ok boomer
“OK Boomer”? – Really?
50 years ago owner manuals used to instruct owners on how to adjust valves, fix brakes, etc.
Now-a-days the owner manuals warn you against drinking the windshield washing fluid.
50 years ago you had to have this conversation using the post office.
Obviously , you’re of the generation that can’t figure out what to do with three pedals.
I’m a Boomer and I approve this message.
Today’s corvette is also much quicker than the ones ‘back in your day’
My only problem with this is. When did trans fluid start going bad after 3 yrs. I have started cars that didnt move in 10 yrs and drove thousands of miles with the OLD trans fluid after making sure it wasnt burnt!
My guess is that there are contaminants in the fluid that accumulate over the first 7000 miles of transmission ware. It’s not the fluid breaking down.
I’ve got a C2 and a C6, both manual shift. Neither one is designed to allow you to “fix it in your garage with a wrench.” The C2 doesn’t even have a transmission drain plug!
Tremec built the C6 transmission, too. Don’t quit your day job.
An Ann Arbor, MI, Chevy dealer where I bought my Corvette charged an outrageous $1150 to change the small cylindrical filter at 13,000 miles. This service took barely ONE HOUR!!! I sent my fervent gripes to top GM management and the dealer’s general manager.
I got my letter. Got a replacement filter already sitting here in a box, bought some correct trans oil fluid per spec. Studied the process, am ready to replace my fluid myself, after 22,500 miles of use since last filter change that was done by the dealer per schedule.
Now that I received my two included services, one engine oil and engine oil filter, and one transmission filter. I am now responsible for all maintenance. Here in my garage.
The corvette C8 is a fantastic modern car. No need to go back to antique mechanicals . Performance, intelligence. Simply amazing.
When you feel the mechanical cut gears downshifting and the engine rumble, when hill assist kicks in to help backing up the driveway or starting from a stop uphill, you sense you are in something very advanced. Probably better to let experienced drivers enjoy it. And keep less experienced drivers in the older antique cars.
Clutch pedal to the far left. Hope that helps you.
So my 2023 second service was done in November with about 5,500 miles on the odo. I did the oil and Tran filter. both were free. I also had the programing done as per the service bulletin for over the air updates.
My car is up to date.
But now I must get the filter done again within the next 1,500- 2,500 miles? Within about 6 – 9 months?
Please, will some one verify this for me
Mike, we still have the Concierge hotline for these questions. But I think you are good until 22,500 more miles after last filter. Just FYI some people were doing trans filters really really early, like 500 to 1000 miles. Those folks probably need a 7500 mile
filter. But I am like you, dealer did it around 6000 and my understanding was no need until another 22,500 passed.
Also do use MECF the mid engine corvette forum, members their have direct access to really good knowledge on our cars.
As a boomer and a C8 owner. I will testify that the C8 is a way better performance car with its advanced 8 speed automatic trans, which can be shifted into manual for my fellow boomers that refuse to move pass rotary dial phones. I have owned manual and at this age I prefer not to clutch and shift.
Yup. What you said!
For those who haven’t driven it, they’ll find themselves loving the trans. I think it’s one of the key features and I relish driving it for that reason.
So if the dealer did the transmission service at 6700 miles and the car now has 15,000 miles does that mean it’s warrantee is void? Was this warrantee requirement changed to be this specific or has it always existed on the 2023 c8?
So to make sure I understand this correctly, there is a DCT filter *and* a transmission filter just the DCT filter? If both, I guess I need replace both of them along with the trans fluid (including the 2 additional quarts I had added for track use). I’m at 14K on my 2022 Z51 and had my initial service done at 2K miles.
I think just the one filter in the DCT. not 2, you are good.
Oh, give me a horse/horses and buggy. Much better than those new fangled things on rubber wheels and with a wheel to steer? Give me those good old reins and whip where you can control the one or two horses tugging your open aired buggy instead of sitting in a closed in box with wanna be horses crunched into an enclosed front compartment that you supposedly control with a single stick. Nah, nothing like a good old whip to spur your ponies on and reins to make go where you want /s/ 🤪.
With todays advance technology when the odometer reaches 7,000, 22500, etc miles why don’t you get an alert on your screen or dash, time to change the transmission filter/fluid. GM – Keep it simple stupid.
you do get an alert, and you also have a percentage count down monitor to keep track.
it is very efficient, but for me personally , I do not like that it wants oil replaced based on time/age and not usage/miles. So you might find me doing a reset if the time ran out, but the miles were not driven.
It would be nice if there was a service app built into the car (and a tab in the My Chevrolet app) that knew every service interval for your specific vehicle. It could remind you when you’re close to needing the service and allow you to confirm that it’s been performed (or automatically check it off if the service department does the work). It’s amazing that they haven’t done something like that.
I own a C3 and a C8 and agree with the original poster. The C8 is a very comfortable ride (except for the noisy run flats) and full of conveniences that make life easy. No shifting just steer the thing. It’s nice to go on a trip with the wife but not half the fun to drive as my C3 (with Tremec 5 speed). The thing is full of computers and transmitters that broadcast your driving habits back to GM, what a crock of nonsense. I’ll keep mine another year and sell it in favor of my C3.
And by the way, there’s s specific procedure required by the dealer to perform when changing the DCT oil , they have equipment that cycles the servos in the transmission while flushing the system. My guess is to flush all the metal chips left in it by the manufacturer. Cost me $870 which appears to be a good price compared to others I have read.
So far I’ve found my 2021 C8 to be pretty friendly machine to work on. There have been a few special tools to pick up including Torx bits and sockets, good jacks (it is very low), and a CAN bus scan/diagnostics tool. The scan tool is essential, make sure that the one you get includes the transmission flush and leak check procedures. There are chats out there identifying the applicable models.