2025 Stingray 2 LT Z51 with 13k miles - Took the car out today to grab something at lunch and had the "idle creep has been disabled" message appear. Car would skip the even gears, shifting from 1 to 3 to 5. I took it to straight to my local dealer here in town without shutting it off, they ran the codes and are saying the transmission is going to need to come out and be looked at to either be repaired or replaced. They are not qualified to do the repair and have suggested a dealer a half hour away in Springfield, MO that supposedly has a dedicated team for Corvettes. I've read a lot on here about transmission issues others have had and some experiences that were downright awful and some that weren't a problem. Just looking for some advice on how I should proceed with this process as I've never had a warranty claim in my life. Thanks for the input in advance, appreciate it!

 

Definitely take it to a dealer with a dedicated C8 tech. Also, it could just be a faulty valve body. Did your car have just 1 new DCT filter replacement in 13K miles or did you have it done more often? I replaced my DCT filter at 2200 miles and will do it again at the required 7-8K mile interval as mine is not there yet. I think the buildup of debris in these transmissions are causing issues with the solenoids. GM should have just required the DCT filter to be replaced far more frequently than they do.

 

Just the one at 7K miles. It was about to go in for another oil change, based on time, at which point I was going to have the DCT filter changed as well.

 

If you will want to take it to the other dealer, I would ask about damaging something further by driving it, might want to get it flat bedded over.
You definitely want an experienced tech working on it.

 

I absolutely agree with JD on a early DCT filter change, no fault is passed on to the unfortunate OP.

GM is lacking having new owners wait 7,500 mi for your first DCT filter change. It's not a surprise that there is a lot of clutch debris occuring the first 1500 to 4000 miles that frequently end up clogging the solenoids and shutting down a good DCT.

Sure a new DCT or valve body is warranty covered, but going through the hassle of time, possible delays and driving around a subpar loaner is not any fun and unacceptable.

Changed my 2020 DCT filter at 1300, 6200, 11,400, 19,800 mi. Since then do a "yearly" DCT filter change which is recommended by Maserati for there MC20, which also uses the Tremec 9080 DCT in our C8's.

Overkill possibly, however the C8 filter is a easy change and with lots of added hp/tq and 39K miles on my C8 been blessed with nothing but quick smooth shifts for 6+ years.

 

If more frequent DCT filter replacement than what the owners manual recommends is so beneficial then why do the vast majority of C8 owners get away with following the GM schedule without problems?

 

The issue with your filter changes is that if you want to maintain the warranty, GM is ADAMANT about that 7500 +- 500 filter change, which you skipped over.

 

If you take it to Springfield, MO, that would be Reliable Chevrolet. They sell a good number of Corvettes each year and should have an experienced C8 tech to work on the car.

 

The exact same thing happened to my 2025. It took better than two weeks to find out that all it needed was a trans reprogram.

 

I was on a long trip (6k+ miles) when my car had a Check Engine Light go on and I lost all the even gears. It was about 7 am and the nearest dealer was about 100 miles away in Bismark ND. I checked Oil Temp, Oil Pressure, Trans Temp, Engine Temp, everything I could think of. I figured that if there was no indication of anything else, I would go ahead and drive to the nearest dealer and hope they were open by the time I arrived. As I drove into the city the gears came back. That is it all started working again. Of course I didn't have an appointment but they said they could maybe fit me in at the end of the day. I talked them into checking the codes and they reset them. I drove the 1300+ miles home without any more incidents..I took it to the dealer when I got home and they did a software update. All good since then.

The point is, you may not need a new tranny. Sometimes the computer just kinda glitches and fixes itself. (REBOOT?) I didn't shut off the car as I was afraid it wouldn't start and I'd be stuck in the middle of nowhere. Population and traffic are thin out there.

 

Majority is true. Not sure vast majority fully applies to the early C8 DCT 20/21 model years. These assemblies were managed by Tremec and faced well-documented transmission issues. GM staff began managing assembly during model year 2022. Also in late 2021 Tremec and GM created the effective HSF. Finally in late 2023 a new stronger and fluid efficient casing was rolled out.

Most original owners have long ago sold their early 2020/2021 C8 in favor of the many other C8 new offerings.

 

Not so. The 7500 mile requirement was not in affect at the time for the 2020.

GM offered the complimentary DCT filter change inside one year or 7500 miles of the car being in service. My C8 was at 6200 miles.

 

I would leave the maintenance schedule intervals to the GM & Tremec engineers & follow what the recommendations are

 

You have to be joking. Do you mean the most confusing maintenance schedule and requirements most owners have ever seen published by any manufacturer? Or possibly the fact that even dealership service departments are all over the place and confused what needs to be done and when? There are more maintenance threads for the C8 DCT than any other vehicle I have ever owned and followed on a public forum. To say it has been extremely confusing for owners is an understatement. So confusing that GM mailed a letter to every owner in an attempt to clarify.

 

This is the single biggest reason my weekend toy is currently not a C8. Anyone can talk about "the vast majority are fine", but I didnt want this threat hanging over my head on top of GM dealer network's flaws. What a shame. The C8 really is an amazing machine.

I hope the 2022 I sold is doing well for its owner. At least it was a pre googlized model.

 

^^This

 

Agree with your point.

We do know as fact that debris is shed into the fluid from driving and that harder driving sheds more debris, making it necessary to change the filter more often. We know that because the filter must be changed every 24 hours of track use - which is probably 2400 miles or so, compared with 7,500, 15000, and 22,500 mile intervals for street use. I think folks driving their car hard on the street might consider more frequent filter changes - hopefully GM consider a range of driving habits for the recommended intervals for street use for the majority of street drivers - but obviously (based on the track use requirement) there must be a point at which driving habits would warrant more frequent changes.

The theory that changing the filter more often is beneficial would appear to be based on
1. debris is the issue with transmission failures,
2. the filter is effective at removing the debris if changed often enough, and
3. when changed at the recommended interval the filter must be overloading and going into bypass - circulating the debris through the lines and valve.

If instead, the filter is inadequate from the get-go, when new, either going into bypass before its full or inadequate media that fails to remove debris, that's a different problem not solved by more frequent replacement.

We really don't know the driving habits of those reporting a failure, but I doubt that the majority were driving their car that hard, and they usually report changing the filter on time. I think this means that either the filter is inadequate for normal street use, or the change interval is too long, or the debris comes from somewhere else, or its not debris.

 

On the owners side it's that they don't read the owners manual, like many today it's easier to ask on line or watch a video than read the instructions. On the dealer side I feel there are two things, one the dealers service writers are just inept and making guesses based on their history with older non DCT transmission service (not to mention other service the C8 needs) but I also feel many recommend services not needed or done more frequently. To put it bluntly I don't trust them.

 

Any of you have the shop save your transmission filter and then cut them apart? Would be interesting to see what and how much they captured.

 

2025?
Has this issue Not been solved yet?
I thought it would make its ugly head known prior to 13K.
Both of mine were under 3K.
Just glad I purchased a 10Y warranty