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I will be getting my allocation pretty soon and am concerned about the issues with the DCT. Have the initial problems been solved with the newer version? Are any 22’s having issues. I read about leaks, valve bodies, codes, contamination and replacement. Still not really understanding enough to feel comfortable. Being an old do it yourself vette restorer I would have a very hard time having dealer take my final and last vette apart…
several years ago I bought a first year sporty Acura. The transmissions started failing on some cars and I always heard a noise in mine but considered myself lucky- eventually all the transmissions failed-I made it to 70k miles and bought another trans and it went out again at the same amount of miles. My friend and a relative liked my Acura so much they bought the same car and their trans failed at varying mileages.
I guess I am asking if someone can summarize why they are actually replacing the transmission and what is mechanically defective? Is it just leaks? Have any issue surfaced on the 22’s ?
I will be getting my allocation pretty soon and am concerned about the issues with the DCT. Have the initial problems been solved with the newer version? Are any 22’s having issues. I read about leaks, valve bodies, codes, contamination and replacement. Still not really understanding enough to feel comfortable. Being an old do it yourself vette restorer I would have a very hard time having dealer take my final and last vette apart…
several years ago I bought a first year sporty Acura. The transmissions started failing on some cars and I always heard a noise in mine but considered myself lucky- eventually all the transmissions failed-I made it to 70k miles and bought another trans and it went out again at the same amount of miles. My friend and a relative liked my Acura so much they bought the same car and their trans failed at varying mileages.
I guess I am asking if someone can summarize why they are actually replacing the transmission and what is mechanically defective? Is it just leaks? Have any issue surfaced on the 22’s ?
So far, all have read here is questionable anecdotal evidence of DCT issues. There seems to be people posting other people's posts so it looks like there are a lot of issues when in fact they are rare.
The same phenomenon occurs on Ferrari boards, Porsche boards, et al. My personal opinion, based on the Ferrari forums, is that a lot of the misinformation and disinformation is posted by people who don't even own a Ferrari. Whether this malicious behavior is due to envy, jealousy, or just plain nutty people is unclear. On the Ferrari forums, the hysteria is also about transmissions. The information they post shows a total lack of understanding of how the Magneti-Marelli-controlled boxes work. The transmission itself is actually rather bullet-proof. They confuse clutch issues, due primarily to abuse and neglect, with the transmission. I suggest you do as much reading on the Tremec box as possible. Knowledge is power and goes a long way towards insulating yourself from hysterical posters.
Also keep in mind that for every poster who reports a problem, there are thousands who have experienced no problems at all.
So far, all have read here is questionable anecdotal evidence of DCT issues. There seems to be people posting other people's posts so it looks like there are a lot of issues when in fact they are rare.
The same phenomenon occurs on Ferrari boards, Porsche boards, et al. My personal opinion, based on the Ferrari forums, is that a lot of the misinformation and disinformation is posted by people who don't even own a Ferrari. Whether this malicious behavior is due to envy, jealousy, or just plain nutty people is unclear. On the Ferrari forums, the hysteria is also about transmissions. The information they post shows a total lack of understanding of how the Magneti-Marelli-controlled boxes work. The transmission itself is actually rather bullet-proof. They confuse clutch issues, due primarily to abuse and neglect, with the transmission. I suggest you do as much reading on the Tremec box as possible. Knowledge is power and goes a long way towards insulating yourself from hysterical posters.
Also keep in mind that for every poster who reports a problem, there are thousands who have experienced no problems at all.
Look, I have read your posts before, you are obviously very educated but the minimizing of the DCT issues has to stop. The matter will not improve unless awareness continues to be raised.
No one is claiming that the issue pervades every single c8. No one is claiming that this is the worst problem ever either. But you know what you are not seeing voiced to this magnitude as a problem? Timing issues, exhaust issues, power steering failure issues, cylinder 1-3-5-7 failure. That is because those issues do not frequently appear to the level that the transmission has.
Get the car, enjoy the car, and if an issue arises let warranty take care of it. I'm nearing 8k miles on my 2021 and its been flawless; easily the best and highest quality car I've ever owned. As a note, I did have my dealership add the 2 quart DCT track-fill during PDI.
I just turned 3k miles in my C8 and had the “free” service at 2500 miles. The factory filter once removed looked good, a slightly darker color in appearance, no metal in the filter. I did have the extra 2 quarts installed during the service. One thing I do notice now is that the trans is quiet as it had a faint whirring sound in the lower gears (1-3) and it shifts “better”. What I mean by better is a more positive shift as in no lag (albeit minute) when going from one gear to the next in manual and any driving mode. Granted it’s only been 500 miles+ since the service was done, but it feels more like my PDK in my 911S….which is very good. I know I’m not the only one that thinks the car should have come from the factory with the extra two quarts of DCT fluid, but in my experience (limited so far), it makes the DCT better….now does it solve the leaks?….probably not, the clogging of the solenoids/valve body?….I bet it at least helps between full trans flushes.
Relax, the car will be fine. Will there be some minor issue that might need an adjustment perhaps. The level of complexity of cars has risen tremendously in the last 4 years. I like many others will tell you we have had few problems. so enjoy the car and enjoy knowing you have a safety blanket of warranty. In regards to your transmission and the entire car for that matter. Break the car in reasonably for the first 1500 miles as the designers suggest. Let the gears bed in, let the motor break in. Now that doesn't mean you have to drive like a snow flake, but no need to try and burn out tires on day one. Break the car in as recommended, read the damn manual several times and you will have a very good feel of the car. I stress the manual, it amazes me how many people who know so little dont even read the manual and info available. Information allows you to understand what the car is doing and you'll be far better off.
You have bought a great machine, enjoy it. Have some fun < after the break in period>
I do know that for a fact that mine and my friends (his car is about 300 apart VIN wise) both leak. I know ours are early versions and they went so far as to change the case design and casting to address leaks like ours. Both perform flawlessly, but they aren't dry on the outside. I don't care what year you buy, if someone nicks an axle seal while installing the drive hubs, they will leak. By now they should have addressed the grit that wasn't cleaned out of some internal parts so I would guess it's getting better. This isn't like the Acura issue where they made it quite a few miles and then failed catastrophically, these are early assembly issues (now that the case was changed, not sure where that leaves me ). When GM has a major component issue that is a new design, it is SOP to pull the entire thing and replace, they don't want a tech at the dealership tearing it apart. Buy your car and enjoy it.
The MAXIMIZING of DCT issues equally has to stop. Let's just list the known issues and best approaches to deal with them.
One thing I think would be useful would be for an owner with a DCT issue to be "armed" with all the right information they need to not be DICKED by the local Chevy dealer if/when they take their vehicle in.
Really bad dealer service has clearly happened to some people, which has been added insult to injury. So the more information we share here the better. Extrapolating this to the sky is falling isn't very useful.
If you have anxiety about buying the C8 over this and you plan to keep the car long term, get a long term warranty.
If you don't plan to keep it long term, skip the extra warranty and if the car fails, you can probably get the dealer to take it off your hands for more than you paid for it. Let them fix it and sell it to someone else.
Here's an example of useful info: You determine that you have a DCTF leak (oil on the garage floor, etc.).
You take your vehicle to the dealer and they state they are going to replace the PAN and SEAL. Do you say, OK let's wait a week or two for those parts to come in and TRY that, or do you say, "Go ahead and order those parts, but in the meantime I want you to perform a LEAK POWDER TEST higher up around the valve body cover where the porosity issues usually are before I leave today!" Why wait for them to try replacing pan covers and gaskets several times when the root cause of the problem is a bad transmission case which they should have properly determined DAY ONE??? Instead, the tech shotguns the problem, and many many do this. It just so happens that the oil runs down the side of the case with gravity and will be present on the pan and seal area, but that doesn't mean the leak originated there.
So far, all have read here is questionable anecdotal evidence of DCT issues. There seems to be people posting other people's posts so it looks like there are a lot of issues when in fact they are rare.
The same phenomenon occurs on Ferrari boards, Porsche boards, et al. My personal opinion, based on the Ferrari forums, is that a lot of the misinformation and disinformation is posted by people who don't even own a Ferrari. Whether this malicious behavior is due to envy, jealousy, or just plain nutty people is unclear. On the Ferrari forums, the hysteria is also about transmissions. The information they post shows a total lack of understanding of how the Magneti-Marelli-controlled boxes work. The transmission itself is actually rather bullet-proof. They confuse clutch issues, due primarily to abuse and neglect, with the transmission. I suggest you do as much reading on the Tremec box as possible. Knowledge is power and goes a long way towards insulating yourself from hysterical posters.
Also keep in mind that for every poster who reports a problem, there are thousands who have experienced no problems at all.
The MAXIMIZING of DCT issues equally has to stop. Let's just list the known issues and best approaches to deal with them.
One thing I think would be useful would be for an owner with a DCT issue to be "armed" with all the right information they need to not be DICKED by the local Chevy dealer if/when they take their vehicle in.
Really bad dealer service has clearly happened to some people, which has been added insult to injury. So the more information we share here the better. Extrapolating this to the sky is falling isn't very useful.
If you have anxiety about buying the C8 over this and you plan to keep the car long term, get a long term warranty.
If you don't plan to keep it long term, skip the extra warranty and if the car fails, you can probably get the dealer to take it off your hands for more than you paid for it. Let them fix it and sell it to someone else.
Here's an example of useful info: You determine that you have a DCTF leak (oil on the garage floor, etc.).
You take your vehicle to the dealer and they state they are going to replace the PAN and SEAL. Do you say, OK let's wait a week or two for those parts to come in and TRY that, or do you say, "Go ahead and order those parts, but in the meantime I want you to perform a LEAK POWDER TEST higher up around the valve body cover where the porosity issues usually are before I leave today!" Why wait for them to try replacing pan covers and gaskets several times when the root cause of the problem is a bad transmission case which they should have properly determined DAY ONE??? Instead, the tech shotguns the problem, and many many do this. It just so happens that the oil runs down the side of the case with gravity and will be present on the pan and seal area, but that doesn't mean the leak originated there.
The source of a leak in a car, especially a car with a full under-tray, is difficult to pin down. You are absolutely correct in wanting to ascertain the original source of the leak. Mechanics will, and do, simply replace things until they think they've solved the problem when they have not. They are flat-rate mechanics. The less time they spend on your car means they can move on to another job and make more money.
They have a dye they can inject into any fluid which will fluoresce under black light to enable tracing a leak back to it's source. But of course, that requires time and effort.
I just borescoped mine. The porosity/problem area looks perfectly clean. Previously it had an oily sheen to it and some bits of trash that looked oil soaked, but that was when it was brand new. Wasn't sure if that was a leak or not.
Haven't had my DCTF fluid level checked though.
This is the area that is most suspect for porosity problems:
This was my car with less than 200 miles on it:
Here is a DCT with a leak, you can see that area is oily, it has a reflective sheen:
I also just used the borescope to grab my data plate and pics of my DCT PAN cover.
It looks like my cover is made from aluminum, but it has been machined in some areas. Definitely doesn't look like stamped steel to me, especially in the area where it is machined. My vehicle as built in MAY 2021.
New borescope pic of the problem area:
It's a frame grab from the video (sorry, my scope sucks), but suffice it to say the mystery yellow bits are gone and it looks clean.
Pic of my data plate:
Example of an earlier bad DCT part# 1120350DEPX0134
Example of a new DCT that was installed to replace bad one: 11211601AEPX0013
Broadcast Code: 1AEP
Source DUNS: 078418860
VPPS Code: 1210000000000X
GM Part #: ????5264
Line Plant Id: 1
Shift Id: 1
Year of Build: 21
Part Sequence #: 0096
Julian Date: 171
Site Id: X
Interestingly, a Julian Date of 171 equates to JUNE 20th, 2021 and I had my car delivered around May 21st.
The julian calendar at GM/TREMEC must be incorrect.
Minimizing or maximizing the problem is irrelevant if the problem continues to exist nearly three years into a product lifecycle. Issues with the DCT should have been corrected already. The issue among a subset of owners on this forum is pervasive enough that it should have GM's full attention.
Look, I have read your posts before, you are obviously very educated but the minimizing of the DCT issues has to stop. The matter will not improve unless awareness continues to be raised.
No one is claiming that the issue pervades every single c8. No one is claiming that this is the worst problem ever either. But you know what you are not seeing voiced to this magnitude as a problem? Timing issues, exhaust issues, power steering failure issues, cylinder 1-3-5-7 failure. That is because those issues do not frequently appear to the level that the transmission has.
ADMIN, please move if their is a better thread for this question.
I'm interested in the statement "cylinder 1-3-5-7 failure". My 2020 has been back to the dealership three times since new. It's a fairly early car. Here's the timeline:
My 2020 must be a “Tigger” when it comes to fuel injectors. I’ve researched this site and the web in general and I don’t find other C8 Corvette owners reporting fuel injector problems. My car’s in the shop for the third time with what appears to be another fuel injector problem.
Timeline:
Took delivery of my 2020 on July 3, 2020. I could not connect for software updates at my house, or “automatically” while sitting near stronger wifi signals. Took to dealership for software updates and they had the car for 10 days while they worked with GM Tech. Let me say, I love my dealership and the tech is topnotch. Nov. 2020:
Just limped home in VIN 3688, check engine light, rough running, "Service ESC" and "Service Traction Control" showing. After turning off engine smelled "burnt" and passenger side intake fan ran for a long time. Car has 895 miles on the odometer.
Update:
Dealership says it's not a broken valve spring and they can't replicate the problem. They're talking to GM about the codes being displayed. I'll go to the dealership on Monday to get a better understanding of what is/is not happening. I seriously felt the symptoms I was having matched what others were getting with a broken valve spring.
.
Update: 12.2.2020, the dealership apologized for bungled communication, GM has authorized replacing all valve springs.
.
Update: 12-5-2020: the dealership and GM Tech diagnosed my problem as a "faulty fuel injector," TAC suggested a compression test and a leak down test. Results within normal specs. All valve springs were inspected with no issues found. #5 injector was replaced and GM authorized all sixteen valve springs be replaced for "customer satisfaction." Car number 3688 did not have a broken valve spring...but, the customer (me) is satisfied. Thank you Integrity Chevrolet and GM.
New problem: March 26, 2021
Car #3688 back in the shop with same symptoms, check engine light, "stumbling" rough running, "Service ESC" and "Service Traction Control" showing. After turning off engine smelled "burnt" and side intake fans ran for a long time. (my dealer Tech did mention that Service ESC and Service Traction Control codes display for many different engine issues).
This has happened at 25mph, 43mph and 55mph. I usually drive in Sport mode, but tried all modes on way back home. Seemed to occur in all drive modes. I may have been mistaken, but, I felt that when I held the shift paddles in neutral mode and revved the engine it didn't miss...not 100% sure of this. I've never done a hard launch...but, have "floored" it a few times on long stretches.
Been in for a week with no progress, the one mechanic I really trust has two Corvettes (not C8s) ahead of me. I'll update with status when fixed.
April 12, 2021
Leaking fuel injector on cylinder #3, fouled spark plug, #3. Replaced both.
This was my second fuel injector problem.
New problem: December 6, 2021
We were on vacation and the car hadn’t been driven for about two weeks. Stuttered while I backed out of the garage to do a little cleanup. December 8th, 2021 had a dealership appointment to replace DCT filter and change DCT fluid. Leaving my driveway the car did the same familiar missing/surging, in addition to something new, abnormal pausing between transmission shifts. I drove on to the dealership.
Car has been at dealership for six days now. Only update from my tech is that there is some problem in the 1-3-5-7 bank and GM Tech has dealer tech sending specific diagnostics for review.
Additional notes: The Corvette has always used Pure (brand name) premium gasoline. The Corvette is always on battery charger when garaged. The car has about 2100 miles on the odometer. I’ve since found out that "Service ESC" and "Service Traction Control" pop up for just about every C8 problem you encounter.
I still love this car…but, I’m being tested. BTW, I’m #1 on the list at this dealership for a C8 Z06 order. I’ve been a Corvette enthusiast since my first one in 1968.
Update: December 14, 2021. Replaced injector #1. It was late when I picked up the car. Paperwork wasn't complete and filed. I'll get a copy tomorrow. Three injectors, all on the right bank. I suppose I should have insisted they replace #7 and get it over with.
**Could this be the same as the above stated Cylinder 1-3-5-7 problems? Anyone?
Thanks,
Daniel (Dan) Smith
River City Corvette Club – Chattanooga
NCM(L) Ambassador
I am the original poster and thank -you to all for responding to my questions about the DCT in regards to my upcoming allocation.
I would like to know if transmissions were replaced for reasons other than leaks and if there is any consistent explanation for what was wrong?? All transmissions have gears,bearings, shafts, pumps, clutches, solenoids and software. Do they tell you what the issue is and how it has been rectified with the new one?? Are the late 21 and 22 cars having issues?
thanks again Greg
I am the original poster and thank -you to all for responding to my questions about the DCT in regards to my upcoming allocation.
I would like to know if transmissions were replaced for reasons other than leaks and if there is any consistent explanation for what was wrong?? All transmissions have gears,bearings, shafts, pumps, clutches, solenoids and software. Do they tell you what the issue is and how it has been rectified with the new one?? Are the late 21 and 22 cars having issues?
thanks again Greg
Sometimes they perform a "flush" cycle and that corrects the problem. Sometimes they replace the valve body and that corrects the problem. Beyond that I don't recall reading where they replaced other parts and corrected the problem. It seems once they ge tot the point of replacing the valve body and it does not corrcet the problem, they replace the entire transmission. I am only echoing things I have read on the forums, I have no direct knowledge.
DCT-Problems/Solutions
). When GM has a major component issue that is a new design, it is SOP to pull the entire thing and replace, they don't want a tech at the dealership tearing it apart. Buy your car and enjoy it.
