Actually, the 2020 manual calls for a check of the fluid life monitor at 45,000 miles and a change "if necessary". Or 3 years or less. It was only later that the manuals said to change it at 45000 miles. I suspect, but have no proof, that the FLM will indicate a change at 45000 miles anyway.

 

I've combined several threads, including this one, to create a comprehensive PDF guide. It contains detailed steps and manuals bound together for easy reference. I trust it will be helpful.

Let me know if anything is missing or needs to be added.

 

Fantastic work!

And as of now, there's no way the obd launch tool replaces GDS2 correct?

 

I changed my DCT fluid and filter at 2450. Car now has 4800 miles on it. The DCT filter life is at 90% and the fluid is at 95%. Based on that, and all else being equal, the filter would time out at 23500 and the fluid at 47000 miles which is close to the requirements in the manual of 22500 and 45000 respectively. Not sure what my track events will do to the life monitor but I'll assess at the end of the season to see if there is a meaningful difference due to the more aggressive driving.

 

Yeah. Its good to find out how the transmission filter life system works. According to the Owner's Manual, it " is based on the number of miles driven as outlined in the Service and Maintenance section." I believe it will only decrement to 0 at 7,500 miles one time. If it is changed early, and reset early, I believe it will now reflect a longer interval. In other words, you could have changed the filter at 10 miles, and reset the filter life monitor and I think it would now reflect a much longer interval and not time out at 7,500 miles, even though if changed at 10 miles, most would say it should still be changed again at 7,500 miles. Many believe that the second change is supposed to be at 22,500 miles, or only 15000 miles after the change at 7,500. And then every 22,500 miles. This was more clear in the 2020-2022 manuals with the tables that showed a filter change at 7,500 miles and then another at 22,500 miles. Its more ambiguous in the later 2023-2024 manuals that say every 22,500 miles after the first one. Verbal statements from GM reps, and some tech-link article material indicate the intent was to change it again at 22,500 miles.

It would be interesting to know what the filter life system does for the second change when it is reset 7,500 miles. Based on your numbers, it appears that 2350 miles beyond the reset event reduced the life by 10%, so 23500 miles beyond the reset event would reduce it to 0. Adding that to the 2450 when it was reset predicts that it will go to 0 at 25900 miles. Had it been reset at 7,500 instead, it probably would go to 31000 miles. Hmmm. I can believe there is granularity in the fluid life system numbers, so it might be shooting for 22.500 miles beyond the reset event.

I personally would (and do) plan on changing the filter between 7000-8000 miles - and I did change mine at 2500 miles. I do not have a filter life monitor on my 2021, but if I did, I would be doing whichever came up first. And, I will likely change it again at 22,500 miles, not 30000. Then every 22,400 miles after.

The wording in the 2024 Manual (which does have a filter life system) says "If the canister filter is replaced more than 800 km (500 mi) prior to the initial 12 000 km (7,500 mi) break in period, the filter still needs to be replaced again within 800 km (500 mi) +/- the 12 000 km (7,500 mi) service interval." I believe one could assume that if the filter was changed early (as you and I both did) the filter life system would have been reset per instructions (if the car has one). So, It could have said "check the filter life system and change if necessary" but it does not.

 

Agreed. For me, I'll never let the DCT filter go to the miles in the OM. It'll be changed at every oil change or every other but not more than 10K miles. I feel it's very cheap insurance especially when tracking the car. I can do a fluid replacement and filter change for less than $400 which I'll just chalk up to the cost of having a street/track car.

 

I'm interested in seeing what people with DCT filter life monitors start reporting. The later manuals just say to follow the filter life monitor or every 22,500 miles other than the first change at 7500 miles. The service bulletins have implied that the second DCT filter change occurs 15K miles after the first change but the later owner's manual are ambiguous. My suspicion is that the DCT filter life monitor will require the DCT filter change every 22,500 miles after the first change which is contrary to what the service bulletins imply (which are also ambiguous about the second change) and what was sid by the 3 amigos during an interview.

As far as I'm concerned, the DCT fluid monitor in the later vehicles will settle whether the 2nd DCT filter change occurs 15K miles or 22,500 after the first DCT filter change.

 

Right. Based on the poster's numbers though, it appears your guess is already confirmed doesn't it? It seems to be on track to recommend the next change at or near 22,500 (actually 23,500) from the first change.

 

It's looking that way but I'd prefer more than a single data point from someone that changed their DCT filter earlier than the required schedule...

 

has anyone used this or similar: Prokomon 3L Transmission Fluid Pump Oil Filling Filler System Fluid Transfer Pump Tool with Adapters (PT1877-2)
[url=http://www.amazon.com/gp/product/B0CW634RCY/ref=ox_sc_saved_image_5?smid=&th=1 ]

Amazon

Amazon

since now I have an air compressor, I found an alternative to manual pumping

 

Haven't used this type of fill device. I've done something similar with filling transmissions that don't have a dip stick and when the fluid comes in a 4 or 5 qt container. I drill a hole big enough in the cap for the fill hose and a small one next to it where I can use my compressor to pressurize the container. Have the fill hose go to the bottom of the container. If I want to stop the fill, I just pull the nozzle away from the small hole. A lot easier than pumping with a cheap one from the auto parts store. For the C8, I just use a hose and a funnel. Necessity is the mother of invention. And being frugal.

 

Awesome write up, thanks!

I have a 2024 so I cannot reset the DCT oil or filter life without GDS2??

 

Why not? Its described in the 2024 Manaul.

 

that’s why I’m confused…Page 11 of michelev’s document says to use GDS2 for 2023+ while prior years can be reset from inside the car?

 

OK. At least I know why you said that. I can't explain the discrepancy though.

 

You only need the GDS2 if you are going to change the DCT filter and want to perform the hydraulic system flush prior to removal and the leak check after filter re-installation.

 

Good information here. But what I want to know is what size tires/wheels are on the 83 Toyota 4x4 in the background picture? These C8s will be in the junk yard long before that Yoda stops running. You can PM me to keep the original post on track.
TIA

 

It's an '80 with 35 x 12.50 - 15's. I've had it for over 3 decades. I just did a Hi-Steer crossover steering conversion last year. I live close to the Rubicon Trail trailhead but haven't been out in a while.

 

Very cool. I missed the round headlights of the 1980. Rectangular 1982 and on. Having a 22RE built for the 83 now. Should be finished any day now. Will be picking it up near you.

Ok, back to the Corvette topics.

 

One thing that concerns me is the different variety of bolts being used. Is it possible to use the wrong one, or are there none of the same diameter/pitch with different lengths? If it is possible to use the wrong fastener, how do you keep track of them?