To me this is a way for GM to lay the costs of this crappy DCT design where the dual clutches shed crap into the fluid and then carried to parts like the shift solenoids causing them to jam up.
Add the dirt made during the build of these is the reason they hide the problem by they're paying for just the external filter replaced at 7,500 miles and not flushing the dirty fluid out and replacing costly DCT fluid
Add the fact to dilute the dirty fluid GM was saying you add another quart of DCT fluid
The C8 Corvette’s dual clutch transmission continues to make headlines for Chevy, but it seems like it’s for all the wrong reasons.
The C8’s DCT has been the one component that C8 owners have had the most issues with since 2020 to now
In addition to these service issues, there still seems to be some confusion over the maintenance schedules as GM keeps changing the rules, what they entail, and how they might apply to earlier C8s versus newer models of years.
Now if you do not follow these rules exactly gives GM a way out to void your DCT warranty
GM wants to clear the air on the maintenance of the C8 transmissions again,
and they have recently begun sending leaders out to owners detailing when to change your transmission’s oil filter.
This is important to follow, as
GM will reject warranty claims on the transmission if all this criteria isn’t met.
The key point to remember is that GM wants to see all transmission oil filters replaced between 7,000-8,000 miles.
The owner’s manual states 7,500 miles, but GM gives us the leeway of 500 miles before or after that mark.
The next change comes at 22,500 miles, and then every additional 22,500 miles afterward at a high cost to having these done
If you had your transmission filter replaced prior to 7,500 miles, it
still needs to be done again between 7,000-8,000 miles. And finally, GM reminds us that even if you have had your transmission replaced, you need to follow these guidelines so that the filter is replaced at 7,500 miles from when you received the replacement.
Here are the rules provided by GM:
• If you already replaced the filter before 7,000 miles (12,000 km) – Replace the filter again by 8,000 miles (13,000 km)
• If you have not replaced the filter and mileage is under 7,000 miles (12,000 kmn) – Replace the filter between 7,000-8,000 miles (12,000-13,000 km)
• If you have not replaced the filter and mileage is over 8,000 miles (13,000 km) – Make an appointment with your dealer.
• If mileage is under 8,000 miles (13,000 km) and your vehicle is 3 or more years old – Make an appointment with your dealer.
The only exception to the 7,000-8,000 mileage rule is if your Driver’s Information Center (DIC) says “Replace Transmission Filter Soon.”
A copy of the GM letter to C8 Owners is below:
Also, part of the confusion stemming from the C8’s transmission service is the question of who pays for it, as GM initially promised to cover that during a “First Maintenance Visit.”
However, many were finding they only met the time requirement for a motor oil change, but not the mileage requirement for the transmission filter change.
For 2024+ Corvettes, the motor oil change and the transmission oil filter change are now split into two separate warranty items.
Earlier in April 2024, GMs issued Service Bulletin no 24-NA-081 that details the Warranty Administration of the C8 Corvette’s Transmission Oil Filter Canister for 2024+ Corvettes and there is a perfect Question and Answer section that goes along with it.
• If you want to replace the Transmission Oil Filter prior to 7,000 miles, you can, but at your own expense.
• If it takes you more than three years to reach the 7,000 miles, the replacement of the transmission filter becomes the financial responsibility of the owner.
• If the Vehicle shows high mileage and the transmission filter has never been replaced, the cost of replacement may be split between GM and Owner.
