Good evening folks,

Recently bought a new 2024 C8 Stingray about two weeks ago and it currently has roughly 400 miles. I’ve been cautious about the transmission due to the issues mentioned in the forum and elsewhere so I’ve been paying extra attention to it.

Today, as I went for a drive, the transmission was acting odd. Let me elaborate..

The transmission was perfectly fine until my drive today. I was driving in manual mode and when I came to a complete stop, I pulled both paddle shifters to disengage the clutch. When I engaged the clutch to proceed forward the car jerked and the transmission made grinding noises immediately after the wheel started moving ( for about one second) .. almost as if the car was about to stall but the computer was struggling to save it from stalling. This was on a flat surface.

I tried it again and same results. I then put the car in park and switched to automatic mode.. same thing, transmission made grinding noises and jerked the car for like one second in 1st gear as soon as the wheel starts turning.

I replicated this about 10-15 times. Same result. This was not happening before. It only happened in 1st gear from a complete stop. Reverse gear worked fine. All other gears worked fine as well.

After replicating it, I decided to drive back home and after about a 10 mile drive, the transmission was back to normal and I was no longer able to replicate the issue.


Is this something to be worried about? Has this happened to any of you on this forum or am I just going crazy? thoughts?

 

Not normal. I would have the dealer see if any codes are being stored (even without a CEL on) and describe the condition to them. If nothing else to get the issue documented.

 

Yep! Sounds like a good idea. It’s happening randomly now.. I set an appointment for tomorrow and recorded it happening… hopefully they can diagnose it and figure out what the problem is instead of saying “everything checks out”

 

Grinding with no movement indicates either incorrect gear engagement or two gears engaging simultaneously. Have the car towed to a good dealer, tell them what happened and further tell them you want them to drop the DCT filter. If you can cut the filter open, tell them you want the removed filter.

 

Would that throw codes? And would they still do it if they end up telling me everything checks out and the car isn’t throwing codes?

(Thanks for the feedback by the way. Really appreciate it)

 

Transmission grinding is a major malfunction and should lead to a diagnostic trouble code.

 

Sweet, I’ll keep it updated here once I find out tomorrow

 

When coming to complete stop with a dct in the c8 no need to pull both paddles in when coming to a stop.

you are confusing the transmission by pulling the paddles in when coming. Stop doing that and just leave the paddles alone and the computer will even manual mode handle the stopping situation .

hope this helps.

 

I left the paddles and "manual mode" alone for the first 1500 miles break-in period on my 2024.
I had nothing happen to me like what you describe.
Let the transmission decide what to do on it's own (it needs to learn your driving habits), until you've got past the first 1500 miles.
See page 176 in the downloadable OM. What to avoid during the break-in period.

 

Using the paddles for neutral when stopping while not necessary, should not cause this problem. There is nothing anywhere in the owners manual that tells you not to do this. For this reason, you need to bring the car in for service and tell them what is happening.

 

Indeed. Maybe I should clarify, when I’m at a red light at a complete stop, I usually pull both paddles to engage neutral. I don’t pull them while coming to a stop; only when I’m at a complete stop do I pull it to go into neutral. This should not confuse the transmission as it is in 1st gear at a complete stop before clutch is being disengaged.

Also, I only do this in manual mode. However, the same issues with the transmission is happening in normal drive mode without ever using the paddle shifters. In the 470 ish miles the car has now, it has only been driven in manual a few times. The majority of it has been in normal drive mode without the use of the paddle shifters. The car has been babied so far. Nothing over 3000-3500 rpm.

Hope this clarifies a bit . I appreciate the insight on not needing to use the disengage clutch feature. I probably won’t be using manual mode anymore until 1500 as suggested. However, I don’t believe that’s a factor in what is happening. A car with barley 500 miles shouldn’t be grinding the way it is..​​​​​​​

 

I pull the paddles when coming to a stop and before the car drops down into 1st gear. Almost 5000 miles on the car with no issues so far. I think I saw something where Tadge does the same when at a stop.

 

All correct, except for the part about confusing the transmission. Grinding should not happen and is cause for a dealer visit. The double paddle declutch is a legitimate operator action described in the manual and should normall not cause grinding or confuse the transmission.

As noted, nothing says it necessary to use the double paddle declutch at a normal stop, regardless of the transmission shift mode. I get that some like to do it in the interest of reducing clutch wear - I believe any difference between the minimal clutch engagement at a stop with the brake applied, and the double paddle declutch is negligible-far more clutch wear is happening with aggressive launches. But thats just me.

From reading the manual, it would appear that the intent of the double paddle declutch is for 1) revving the engine up at a stop light (because of the comical caution about exhaust noise in excess of local laws), 2) rapid exit (which is a form of aggressive launch and should probably not be done before 1500 miles), and 3)in 2024 there is also a manual launch feature that can be initiated from the double paddle declutch - again an aggressive launch that should probably not be attempted before 1500 miles.

 

Update:

Took it to the dealership. Car threw a bunch of codes for infotainment system but nothing for transmission. They took it for a short test drive and stated they could not replicate the issue and the tech felt a bit of grind but that was normal for DCT..

I showed them several videos of it happening and they acknowledged it was a not normal. They stated that at this time there is nothing they can do because the tech could not replicate it.

They told me to bring it back if it happens again. I told them the problem is periodic.. it stops then starts then stops again. They understood and said it was one of those unfortunate situations.

 

They did start a TAC case and said if it happens again, the TAC case is already created with GM