Should I add 2 quarts of trans fluid?

[C7GS]

It is not recommended for 2024s because the transmission case has been redesigned, with added baffles to limit the trans fluid from sloshing around in high-g cornering, exposing the pickup. Nothing else about the transmission is different.

The normal and only recommended fill level for all 2024 models is the same as the "normal" level used since 2020, minus the two extra quarts for tracking.

That further substantiates that the extra two quarts are not necessary in street use and only for HPDE use. I will not be adding the two extra quarts when our car is in this week for the 7500-mile service including fluid flush and canister filter change.

I am greatly appreciative of this information.

I missed this completely. Could someone please provide me with the GM documentation of the information?

I will also search...

Thanks, Paul

[Foosh]

I am greatly appreciative of this information.

I missed this completely. Could someone please provide me with the GM documentation of the information?

I will also search...

Thanks, Paul

It should be found in the 2024 Owner's Manual. In prior MY manuals, adding the extra 2 quarts for track use was in a section specifying required prep for track use. I suspect that section will be deleted in the 2024 manual.

The information I passed on above was in a presentation delivered by Corvette engineering personnel at the last NCM "Bash" earlier this year, where it was clearly stated no extra trans fluid is necessary in 2024 models. I believe those slides are published on this site somewhere.

[JB]

The techs should not add two quarts of fluid to a 2024 c8 stingray or any car that has a 2024 transmission.


I have a 2024 transmission in my stingray and they will not add the two quarts to the transmission
.

enjoy your car as is.

[C7GS]

It should be found in the 2024 Owner's Manual. In prior MY manuals, adding the extra 2 quarts for track use was in a section specifying required prep for track use. I suspect that section will be deleted in the 2024 manual.

The information I passed on above was in a presentation delivered by Corvette engineering personnel at the last NCM "Bash" earlier this year, where it was clearly stated no extra trans fluid is necessary in 2024 models. I believe those slides are published on this site somewhere.

Thanks Guys

I don't intend to spam this thread or beat this dead horse, but I am seriously trying to learn from the known evidence. The information here, while sometimes taxing to locate and interpret, is very valuable, and a major strength of this forum.

Regardless of the high level of competence, of the factor build team, I plan to double-check the transmissions fluid level soon after delivery. This is easy to accomplish, good insurance, and peace of mind for myself.

I have not found any information mentioned at the 2023 Corvette BASH, about any changes to the 2024 Stingray's transmission build characteristics, but I'm sure you are correct, that there is a difference and this information was somewhere presented at the 2023 BASH?

What I did confirm, is that the 2024 manual does simplify the transmission fluid level question. (See P. 161) Including track usage, even if the fluid and filter life are shortened by either the DIC fluid life indicator or by an individuals known "24hr. hard track usage."

"Dual Clutch Transmission (DCT) Fluid The transmission fluid and external canister filter should be changed after every 24 hours of track use. Change the fluid and external canister filter as soon as possible if prompted by the transmission fluid life monitor that remaining fluid life is low. With the transmission at factory fluid fill, there is no additional fluid needed for track usage. Any transmission level set or change should be performed at your dealer."

Cheers with the beers

[Neogenesis]

The techs should not add two quarts of fluid to a 2024 c8 stingray or any car that has a 2024 transmission.


I have a 2024 transmission in my stingray and they will not add the two quarts to the transmission
.

enjoy your car as is.

Did you have your transmission replaced?

[JerryU]

My opinion - If you don't track your car the additional 2 quart overfill doesn't have any benefit. It is a band-aid for certain conditions only encountered on the track. But the engineers evaluated it and it doesn't really hurt anything other than a slight reduction in mileage so if it makes you feel better then do it.

All indications are the 2024 DCTs don't have more fluid them than the earlier DCTs. GM fixed the problem with the oil pickup with the revised case design. The Z06 DCTs don't appear to have more fluid.

I agree. As you say a Band-Aid for what GM no doubt found late in testing. The fellow in Carlise is one who said why add if Tracking, "If Going Downhill and Turning," as they may have found at say Laguna Seca Corkscrew where you do both.
Here are some points re why not add if not tracking:

In the Z06 reveal, Aaron Link (Global Vehicle Performance Manager) speaking w blogger Speed Phenom, who asked:
“do we still have to add 2 extra quarts of trans fluid?”
Link replies: ‘No, there is no need to “overfill the transmission”. ‘On every track we have run the transmission performed well and confident no need for additional oil.

There is a good video by a C8 tech who discusses the ~50 DCT's he has examined with CELs. Says several times NOT to add extra unless Tracking.

Will cover other points with pics:

Yep, as GM probably identified in final Track Testing (why the fill plug is in a hard to reach place to add the two extra quarts AND no fill check plug once added.) It is cresting a hill and making a high "g" turn while going downhill may need to keep fluid under the flid pump pick-up. The Laguna Seca Corkscrew is a classic!

Oil levels do not need to be very high for gears, just adds drag and can cause oil foam.



Good pic of Bank's engineer showing what dif fluid looks like at relatively low speeds. At higher speeds and with lower viscosity DCT Fluid there is a cloud of lubricant for all gears! As Noted in the video these pics came from, oil foam detracts from fluid lubricating ability! They found a special case cover design was needed to minimize aeration and foaming.

[JerryU]

You're going to add 2 quarts to a 2024? It isn't required (nor is it technically authorized) for 2024 DCTs.

Been reading the 2024 owner's manual for my planned E-Ray. This is what it states re DCT Fluid:

Dual Clutch Transmission (DCT) Fluid
The transmission fluid and external canister
filter should be changed after every 24 hours
of track use. Change the fluid and external
canister filter as soon as possible if
prompted by the transmission fluid life
monitor that remaining fluid life is low.
With the transmission at factory fluid fill,
there is no additional fluid needed for track
usage.

The is NO OVERFILL as was the case with the prior to 2024 and C8 Z06 DCT's. They added baffles etc to the new case to prevent fluid from possibly leaving the fluid pick up at the bottom on the DCT pan.

Of interest, my C6 Z51 had a patented oil pan with baffles to prevent fluid from leaving the oil pick-up with its wet sump! Both my C7s used a dry sump that keep oil pressure regardless of length of high lateral "g" drive. I recall the 270-degree highway entrance ramp I took every day with my wet Sump Datsun 260Z. Could see a dip in the oil pressure gauge at the end of that turn. Always concerned!

In drag racing at high "g" launch hinged baffles are used to keep engine oil under the oil pick-up!

[topfuelman]

The simple fact that the car gets worse mileage with the added fluid should tell you something...More drag inside the transaxle causes what...More heat which causes what...Early transmission failure possibly? JUST SAY NO!! (unless you're tracking it) JMHO