Some people have switched from the expensive ACDelco FFL-4 to the Valvoline DCT fluid. Valvoline claims that their fluid is a replacement for FFL-4 fluid but, so far, neither GM nor Tremec have approved it for use in the C8 TR-9080 DCT. I thought I'd create a poll to capture people's experience that are using or have used the Valvoline fluid. The results would be useful for people considering switching to the Valvoline DCT fluid.

 

I will be making the switch once my car is outside the 5/60 powertrain warranty, for whatever that's worth.

 

^^^
I have an extend warranty so I'll probably wait until that has expired if I switch.

 

Same here.

 

I screwed up my poll questions (brain fart) and a poll can't be edited (or at least I couldn't figure out how to do it). Please disregard this poll respond to the other poll.

Moderators: Please lock, delete, or merge this post with my other post as appropriate.
Thanks

Edit: Ignore this message, @Zymurgy fixed the poll for me. The other poll was removed.

 

Uh Oh, did the wrong poll get deleted? I no longer see the other poll.

 

Yeah, I see. It does not include the Yes - but I don't track the car. Oh well.

 

Please PM me the question you want on this poll. I can edit them for you.

 

Thanks for correcting the poll for me!

 

Fuchs, which makes the AC Delco fluid, has multiple FFL-4 fluids tailored to different manufacturer requirements. I'm not sure Valvoline saying their fluid is a "replacement" for FFL-4 means it meets all of Tremec's specs.

 

I just changed mine (2020) and used the AC Delco...

 

I'm going to keep using the AC Delco fluid until an oil sample shows there is a fluid superior to the OEM stuff. I'm not concerned with warranty but when an OEM honors warranty claims knowing the car has been tracked (and the owner followed all of the OEM track requirements), I have much more faith in stock stuff.

 

This is my experience with the Valvoline DCT fluid in the C8.

My daughter has a 2020 Corvette Z51 and I have a 2023 Corvette Z51, and a friend has a 2023 Z51 also. They are all completely stock except for upgraded brake rotors. We track our cars many times per year on road courses with 20-30 minute sessions. When running similar lap times, the cars come off track with engine and transmission temps within 2-5 degrees of each other. Last year I took my 2023 Z51 to a Chevrolet dealership for a DCT service plus the two extra quarts. At the next track event, my transmission threw temp high warnings on the dash. I would drive around after the session to cool the car and the transmission temps would bounce around - I suspect because it was boiling into vapor. And the transmission was consistently running 15-30 degrees hotter than my friends. Also experienced many hard or janky shifts. Same lap times - literally racing each other on track the whole time.

When I got home, I looked at the paperwork and figured out they used Valvoline DCT part # 888705. I had no idea a Chevrolet dealership would ever use anything but OEM fluids. I finally convinced them the oil is the problem and they need to swap it out for AC Delco FFL-4 plus the 2 extra quarts again. They did this for free. I went back to the track and it was immediately better, but not fully back to normal. Then at the next warmer event it was back to the same problem - over temps, hard/bad shifts/etc. Now I am trying to get them to replace my transmission because it's steadily getting worse.

These cars do not overheat. Neither transmission nor Engine. We have run them at High Plains Raceway in 105 degree ambient temps(before the fluid fiasco). Nearly every other car there that weekend had heat issues. None of the C8s skipped a beat the entire weekend.

Note - the 2023 Track Prep document says this

"Any transmission level set or change should be performed at
your dealer. The transmission fluid used in the dual clutch
transmission is a specific transmission fluid. Use of unapproved
fluid may cause damage to the transmission. See your dealer for
the proper transmission fluid"

I would have specified AC Delco FFL-4 to be put in my car had I known I needed to. The Valvoline DCT fluid is definitely cheaper. I had never heard of it until this issue and I wish I still had never heard of it. I never experienced any issues with it during road driving, only at the track. And I never checked if it runs hotter on the street versus the other cars. Maybe it's ok for the street if some street-only people want to give it a shot? Never again under any circumstances for me.

Just wanted to give everyone a real world data point.

 

So....is the dealer that put in the Valvoline fluid going to replace the transmission? You said its not shifting right any more. Looks like it is still under warranty. Curious to see if GM will cover it when a different fluid was used. But since the dealer did it......?

We'll never know if the issue was a coincidence, or a result of the fluid, or a result of not being filled fully (as someone suggested).GM reps have stated the "overfill" is really just to avoid pump starvation in certain maneuvers that are difficult to reproduce even in track situations. And the newer ones with a case and pan mod to hold the fluid near the the intake don't even need the 2 liter overfill for track use - and they don't typically overheat or suffer damage. Point being even if the dealer only added the normal fill, that should not have caused damage (though the temperature maybe would be higher, I don't know???). Its seem unlikely that the dealer under-filled it and also failed to add 2 liters (but possible I suppose).

 

Do a search, has happened before poster reported that GM engineer traced it back to the fact the overfill caused the splash to hit the temp sensor. Many track guys use 888705 Valvoline, with no problems. The sky is not falling. Back to our regularly scheduled program.