I had the dealer do my first (free) oil change and DCT filter change at 6579 miles in Nov 2023. At that time there was no directive to change it no earlier than 7K miles i.e 7500+-500 miles. I learned of the new requirement (to change the filter again before 8K miles if it was changed earlier than 7K miles) when my car had a bit over 9K miles on it. I currently have about 10K miles on my 2023 (getting ready to do the 3 year fluid change).

My first question is how can GM issue a requirement when some cars like mine had already had their DCT filter changed outside of the minimum mile requirement but over the maximum mileage?

I'm planning to take the car in for the fluid change in Aug this year at its 3 year birthday. I'm wondering if I should go ahead and change the DCT now or after the fluid change. I was going to do it myself to save a few bucks or should I let the dealer handle both item in August? It seems no matter what I do GM could say I failed to do the required maintenance in a timely manner, but again I had no change to do that since the new requirements were issued after my car had over 8K miles. I just don't want to void my warranty.



Thanks

 

First, you can't go back in time. Second they don't void your warranty but may refuse to pay for repairs under warranty. That said unless you have a problem it doesn't matter.

 

First: I knew when I had my DCT filter charged on GM's Dime year 1 with ~3000 miles it was required again at 7500 miles. There is some debate on the exact time the Doc below published BUT when I had my DCT fluid Changed Year 3 with ~8000 miles I knew in August 2023 when that occurred (and so did the C8 Trained Tech I use) that the DCT filter required changing AND I could wait until 8000 miles.

You may have learned late BUT it was known when I had my DCT filter charge year 1 with ~3000 miles it was needed again at 7500 miles to maintain DCT warranty. Yep did not know the +/-500 miles until later but positively knew well before I had mine changed again at ~8000 miles year 3 in August 2023. Well before that I believe all of 2023, that is why I waited to about end year 3 to get max time for the DCT Fluid change required every 3 years regardless of low miles.

So NOT accurate to say anytime in 2023 "At that time there was no directive to change it no earlier than 7K miles i.e 7500+-500 miles."


Yep when I paid for my 3 year service I knew a new DCT Filter was required and my having it changed at ~3000 miles year one gained only my peace of mind! And so did my C8 Trained Tech. I waited till end year 3 to get max time on the new fluid charge and for my engine oil/filter requiring change.

 

Yes GM said change the DCT filter 7500 miles but similarly I change my engine oil a bit earlier than recommended. For example If an engine oil change requirement is to change at 7,500 miles and I change it at 6K miles, I know of no manufacturer's make or model that would tell you it's required to change it again at 7,500. How would one expect to know this about the DCT filter until the notice was communicated and then, for me, it was too late.

I stand by my statement that at the time I had my filter changed the +-500 mile requirement had not been communicated. I received my notice way after that point and I'm interested to know what GM's stance would be if I had a failure. As the other poster stated it won't be a problem if I don't but still I was curious to what other people thought if a problem did happen.

 

Not paying for an item that is covered under warranty is an example of voiding your warranty.

 

You and your Tech may not have known BUT it was clear to me well before August 2023 when I had mine done it was +/- 500 miles. I believe that was known sometime in 2022!

Here is why:
I had mine done in 2021 when my C8 was 1 year old with ~3000 miles. Because:

• Folks were getting DCT CELs and when they brought the car to the dealer their tech was told by GM Service just do a Flush, no new filter no change of fluid just a FLUSH. It most cases it was reported the CEL was gone and did not come back.
• When I crawled into my garage at 2 to 3 mph watching the driver mirror to garage door molding gap, keeping it below 2 inches, there was a chatter or somewhat jumpy movement. After ~1000 miles it was perfectly smooth. I attributed that to the high spots wearing off the 1st gear (and all odd gear) clutch. I wanted to get that clutch debris out of the trans. Mostly took advantage of the GM Free offer to get a free Flush.

There was a lot of discussion on the forum in 2020/2021 about the tolerance in the 7500 miles. A Member asked a GM Exec at a race and was told +/- 500 miles. He reported. Soon after it was published. May be the Doc I posted BUT I knew in all of 2023 which is why I waited until I had ~8000 miles.

WILL GM Deny Coverage?
If the DCT fails GM may not pay as IMO Opinion, from understanding GM supplier agreements for things like Transmissions, Steering etc they buy, the Supplier signs an agreement saying for GM's Warranty period they will replace the product AND reimburse GM for what they allow dealers to charge them for the replacement.

The supplier can specify "required maintenance." So IMO that is Tremec's mileage/range and decision. Heck I self insure for many things BUT would not for a $20,000 DCT. Hope your DCT doesn't fail during warranty!

PS: You are not the 1st person to raise the issue. The answer doesn't charge based on when you and your tech knew!

 

Jerry, If one didn't participate in Corvette forums or social media concerning C8s, how would they have known in 2023 that if the DCT filter was changed earlier than 7K miles if would need to be changed again between 7K and 8K miles?

 

To me voiding your warranty is more big picture and happens prior to a situation requiring repair such as selling your Z06 when you had it less than six months.

Denying warranty coverage when something fails is different.

That’s my opinion.

 

[QUOTE=JerryU;1608915012]

• Folks were getting DCT CELs and when they brought the car to the dealer their tech was told by GM Service just do a Flush, no new filter no change of fluid just a FLUSH. It most cases it was reported the CEL was gone and did not come back.
• I wanted to get that clutch debris out of the trans. Mostly took advantage of the GM Free offer to get a free Flush.

Driving the car mimics the flush procedure [according to Corvette engineer, Josh Holder], so the dealer doing the flush without changing the filter leaves that debris in the transmission and is the same as simply driving the car and not bothering with a service visit. At 300 miles, my '22 Z51 HTC got a CEL and an "idle creep disabled" message on the DIC. The car drove normally and the CEL cleared itself later the same day. I pulled the codes and got P2854, indicating debris interfering with the solenoids. I figured it was a fluke and mentioned it when I brought the car in for its "first service" at 7,843 miles. It has been over 43,000 worry-free miles since then.

 

GM notified affected customers by letter in 2024. If one replaced their DCT filter early and it has not been changed again and their car has over 8,000 miles on the odometer , I would think that they would be expected to change it again as soon as practicable after receiving this letter. Pro hint: Do not perform scheduled maintenance ahead-of-schedule.

 

The OP's point is that he changed his filter at 6579 miles in Nov 2023, and when he received the letter he already had 9K miles on his car. He can't go back in time to meet comply with the letter and the letter doesn't say what to do if you changed your filter early and now have over 8K miles on the car.

And the wording in the letter is misleading in stating it is a reminder. It is only a reminder for those with 2025 or later cars. If you use the link in the letter to review the maintenance requirements for the DCT there is nothing in 2024 or earlier manuals stating if you changed your DCT filter earlier than 7K miles you need to change it again between 7K and 8K miles.

 

Then you rely on the dealer who is supposed to know. The Doc I quoted is a Dealer Doc. But all knew it was supposed to be changed at 7500 miles. You can't just "Guess" at what the tolerance was!

 

And I agree the dealer should known in fall of 2023 and told the OP he would have to change the filter again if changed early. But dealers often tell their customers incorrect information and I've seen some posts here where people were told some things that are in violation of maintenance requirements. And the response here is often to RTFM which wouldn't have helped in the OP's case.

You have to know there is a tolerance to be guessing at a tolerance. My wife's Avalon says to change the engine oil every 7,500 miles. If I change it at 5,000 miles and then at 12,500 miles am I making up a tolerance because I didn't change it at 7,500 miles?

 

Its pretty clear in the owners manual of my 2023, page 304. It says to change it at 7500 miles, the way I comprehend this, if it was allowed to be changed sooner it would say so, so my assumption was it has to be changed at 7500 miles, even before the letter was sent out confirming this. Could they have made it clearer? Yes, they could have

 

That caution note isn't in my 2020 owner's manual. And many people would read that note and think something like "wow, that sounds important. I'm going to over maintain and change my filter at 5K and 10K miles to be sure I don't have any problems".

 

Agree Dealer's were often giving incorrect information. Even a top volume deal said they only do a Flush with the DCT filter if there is a DCT CEL etc! But many misstate the requirements that are clear. I blame the Owner's Manual that now makes you hunt for the maintenance requirements. And how do you know if you missed one? Thru 2022 there was at least the Maintenance Table (with footnotes) that answered most questions. BUT that did not define the tolerance on the required 7500 mile DCT filter change (and should have.)

My recent experience with the Wrong Statements in the 2024 Owner's Manual re charging the E-Ray batteries (EV and 12 volt starter) just reinforce my opinion it's being outsourced! The 1st 2024 Owner's Manual said: If the EV Hybrid Battery is low it may need to be put on a charger! That's NOT possible. It also said if the E-Ray sits longer than a week connect a charger or remove the negative battery terminal.

The 2025 Manual corrected those misstatements.

• It makes no mention of charging the EV Hybrid battery other than via the alternator.
• The new statement about the time to use a charger on the 12 volt Li-Ion battery states:

 

Yes you are past the window, but you received the clarification about the window after it was too late to comply. And the window is not stated in your manual - it did not appear until the 2024 manuals. So anyway, if this happened to me, I would still go ahead and change it again, now.

As the term void, and the discussion about that - its a bit of a technicality. GM does not need to void the warranty. The warranty already says what is covered and what is not covered. One thing that is not covered is damage caused by lack of maintenance. So, if someone has 20000 miles and never changed the DCT filter, and has a transmission issue, GM is likely to deny the warranty claim citing that the damage was cause by lack of maintenance. But they would still cover other things.

If you change your filter at 6500 miles and then at 10000 miles, and have a transmission issue, its very very unlikely that it was caused by failure to perform maintenance. But, if you changed it at 6500 miles and then go all they way to 22,500 before the next filter change, and you have a transmission issue at 21000 miles, well....???

Edit: Adding to this - the warranty manual specifically states "GM recommends that you retain all maintenance receipts for your vehicle, but GM cannot deny warranty coverage solely for the lack of receipts or for your failure to ensure the performance of all scheduled maintenance." The can and will deny a claim if the lack of maintenance caused the issue.

 

personally I think changing @ 7500 and then waiting all the way to 22,500 to change it again is tap dancing through the graveyard. I think I’ll actually pay for a change in the DCT filter at about 14K or so just to make me feel better.

Andy I’d appreciate your input on this… Does this make sense?

 

Changing at 7,500 and 22,500 miles complies with GMs schedule. Changing it more often won't hurt. The Maserati MC20 manual calls for a DCT filter change every 9320 (forever, with the same transmission.

 

That kind of thinking is why people changed before the 7500 in the manual and the second time after the 7000-8000 window which is out of the GM requirement now published. Personally I think doing a little more maintenance is okay and even if the OP has a problem GM should cover it. If they didn't I'm pretty sure arbitration would side with me.