DCT Fluid
Heel & Toe
Joined: Mar 2025
Posts: 16
Likes: 7
From: Bethlehem pa
Thank you!!!
I don't know "what every one is doing", but here are the minimum requirements from the Owner's Manual - and the filter and fluid are on separate schedules.
Filter - change between 7000-8000 miles even if done earlier, then change it at 22,500 miles on the odometer, then every 22,500 miles (or less is ok here) thereafter. Or when you filter life monitor says to if you have one - but never go pasts the above mileages.
Fluid - change when the fluid life monitor says to, or 45000 miles, or at least every three years whichever is first. The fluid life monitor does not include time so you must observe that yourself.
Fluid and filter are to be changed every 24 hours of track use if you track.
Filter - change between 7000-8000 miles even if done earlier, then change it at 22,500 miles on the odometer, then every 22,500 miles (or less is ok here) thereafter. Or when you filter life monitor says to if you have one - but never go pasts the above mileages.
Fluid - change when the fluid life monitor says to, or 45000 miles, or at least every three years whichever is first. The fluid life monitor does not include time so you must observe that yourself.
Fluid and filter are to be changed every 24 hours of track use if you track.
Thank you
Joe
Race Director
Joined: Aug 2016
Posts: 12,721
Likes: 10,151
From: Garden Valley CA
this is true if you know what the tolerances are within the equipment. That’s why I’m asking how dirty is too dirty. It’s probably true that GM won’t print it because of lawsuits.
Are there any transmissions that failed after the first flush/filter change? This could be hard to know, but if they are still failing then the flush/filter change may not be the cure. Or if no more failures then the flush/filter change may fix it?
Sorry for all the questions I’m new and you guys have 5 years of info before me.
Joe
Are there any transmissions that failed after the first flush/filter change? This could be hard to know, but if they are still failing then the flush/filter change may not be the cure. Or if no more failures then the flush/filter change may fix it?
Sorry for all the questions I’m new and you guys have 5 years of info before me.
Joe
Heel & Toe
Joined: Mar 2025
Posts: 16
Likes: 7
From: Bethlehem pa
Damn
that’s not good to hear but let’s hope that’s the exception to the norm.
Thank you
Joe
Hoon
Joined: May 2000
Posts: 717
Likes: 755
From: Krypton
What your transmission does while driving IS NOT THE SAME as the HSF. Stop the BS right here. I posted in the past how to accomplish running maximum flow through the filter and this came to me straight from Tremec engineering in a three way conversation. Maybe no one was paying attention. Under certain driving conditions, the pump output will go to max and push max flow fluid through the filter. You can replicate this with the car stationary as well. However, fluid will not cycle through the valve body solenoids and oil channels. Holder's statements were very misleading. There is a lot of BS circulating in the Corvette community. Stop spreading falsehoods.
I do not understand the need to keep endlessly discussing and speculating on HSF this or that. No need to guess or interpret what anyone says or doesn't say and no need to read between the lines......just run the HSF procedure as specified and be done. If you can afford these cars, you can afford $250 for a scan tool to properly do the HSF procedure.
Mitchell_B has posted several threads on the MDI2 + I've bought no fewer than 4-different scan tools for C8/Global-B vehicles, posted threads about all of them, and settled on the $250 TOPDON RLink + a $50 Delco TDS subscription as an excellent solution for ALL C8 owners to manage and program their cars.
The topic of HSF =
Race Director
Joined: Aug 2016
Posts: 12,721
Likes: 10,151
From: Garden Valley CA
The good news is once you make it past 10K miles or so you are much less likely to have a DCT problem, most of the problems seem to be infant mortality and are covered under warranty.
Racer
Joined: Aug 2020
Posts: 412
Likes: 219
From: San Diego, CA
Question(s):
1) Does the "$250 TOPDON RLink + a $50 Delco TDS subscription" work on a 2020 Corvette C8 Z51 - emphasis on 2020?
2) If it does work on a 2020 C8 will it also perform the "Leak Test" procedure?
3) Lastly, which model TOPDON RLink are you referring to?
THX for your consideration & time.
1) Does the "$250 TOPDON RLink + a $50 Delco TDS subscription" work on a 2020 Corvette C8 Z51 - emphasis on 2020?
2) If it does work on a 2020 C8 will it also perform the "Leak Test" procedure?
3) Lastly, which model TOPDON RLink are you referring to?
THX for your consideration & time.
Instructor
Joined: Jul 2016
Posts: 125
Likes: 32
From: North Carolina
Completely agree.
I do not understand the need to keep endlessly discussing and speculating on HSF this or that. No need to guess or interpret what anyone says or doesn't say and no need to read between the lines......just run the HSF procedure as specified and be done. If you can afford these cars, you can afford $250 for a scan tool to properly do the HSF procedure.
Mitchell_B has posted several threads on the MDI2 + I've bought no fewer than 4-different scan tools for C8/Global-B vehicles, posted threads about all of them, and settled on the $250 TOPDON RLink + a $50 Delco TDS subscription as an excellent solution for ALL C8 owners to manage and program their cars.
The topic of HSF =
I do not understand the need to keep endlessly discussing and speculating on HSF this or that. No need to guess or interpret what anyone says or doesn't say and no need to read between the lines......just run the HSF procedure as specified and be done. If you can afford these cars, you can afford $250 for a scan tool to properly do the HSF procedure.
Mitchell_B has posted several threads on the MDI2 + I've bought no fewer than 4-different scan tools for C8/Global-B vehicles, posted threads about all of them, and settled on the $250 TOPDON RLink + a $50 Delco TDS subscription as an excellent solution for ALL C8 owners to manage and program their cars.
The topic of HSF =
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Hoon
Joined: May 2000
Posts: 717
Likes: 755
From: Krypton
Question(s):
1) Does the "$250 TOPDON RLink + a $50 Delco TDS subscription" work on a 2020 Corvette C8 Z51 - emphasis on 2020?
2) If it does work on a 2020 C8 will it also perform the "Leak Test" procedure?
3) Lastly, which model TOPDON RLink are you referring to?
THX for your consideration & time.
1) Does the "$250 TOPDON RLink + a $50 Delco TDS subscription" work on a 2020 Corvette C8 Z51 - emphasis on 2020?
2) If it does work on a 2020 C8 will it also perform the "Leak Test" procedure?
3) Lastly, which model TOPDON RLink are you referring to?
THX for your consideration & time.
I've used it for SPS2 programming and GDS2 diags on my own 2025 ERay, 2024 Duramax truck, 2025 Equinox, and a friends 2021 Stingray.
Heel & Toe
Joined: Mar 2025
Posts: 16
Likes: 7
From: Bethlehem pa
Trans fluid analysis
Guys
Happy Labor Day weekend, I promised I would share the lab work. I uploaded the report and On the bottom right you can see the particulate information. My guess is the particulate matter is low. What do you think?
Joe
Happy Labor Day weekend, I promised I would share the lab work. I uploaded the report and On the bottom right you can see the particulate information. My guess is the particulate matter is low. What do you think?
Joe
Drifting
Joined: Feb 2023
Posts: 1,353
Likes: 1,115
The numbers in your report are not great.
Thread Starter
Melting Slicks
Joined: Jun 2001
Posts: 2,261
Likes: 546
Yes, and been trying to convince myself to leave the filter and pan alone. When I asked the engine oil analysis tech about the Filter Mag magnets and the effect on the engine oil test. He said, "no one has ever asked that question before". And thought it would not change because of the fact anything bigger than 30 micron would be caught in the filter anyway. My Wix 10290 claims 21 micron. I can tell you that there is a faint outline around all eight magnets. On the 5 filters I have dissected over the last 7,653 miles. If anyone has more info on the dct oil analysis, please post. Mitch, I am planning to change the DCT oil and filter in 2026 early, at 2 years instead of 3. Probably less than 3000 miles on this service. Tell me more about the ISO4406.99 reporting standard. And what to watch, Thanks.
Heel & Toe
Joined: Mar 2025
Posts: 16
Likes: 7
From: Bethlehem pa
To say it is not great you must know what is good for these transmissions. What numbers would be expected for the fluid from the DCT?
Joe
Drifting
Joined: Feb 2023
Posts: 1,353
Likes: 1,115
Adding to this discussion - after running the HSF and then changing my DCT fluid and filter in July of 2025, I will again run the HSF with a filter change before and after the flush before the end of the year. I will send out for analysis oil samples taken both before and after the HSF and filter change. The accumulated mileage since this last service is 2214 miles. The particle test will show how effective the Tremec filtration setup works at maintaining oil cleanliness.
Focusing mainly on engine life, this addresses the issue of hydraulic system cleanliness - which is just as critical in your DCT:
Focusing mainly on engine life, this addresses the issue of hydraulic system cleanliness - which is just as critical in your DCT:
Safety Car
Joined: Jun 2006
Posts: 4,008
Likes: 1,487
From: Ashland, OH
Every one of my new cars gets its first oil change around 1k mi, then at 3k,t hen at 5k. Then 5k from there on out. When I had my 25 SR both first oil change and DCT filter was at 1,225mi.