I don't disagree with you. I think the problem rate on the DCT is significantly higher than either GM or Tremec planned for and budgeted for. But I think it's still a very small percentage. I obviously have no inside knowledge, but I would guess GM's target for DCT warranty claims is under 1%. Probably well under. So if 3% of DCTs have needed some service or replacement, that's a huge issue for GM and Tremec, but still affects a very small number of C8 buyers.

 

Oh I absolutely agree with that as well. When things go wrong is when people yell the loudest, so there's definitely some biasing here.

It's also why despite the numerous reports I still stuck with it and purchased a C8. Most of my previous cars have been bulletproof Japanese makes, so reliability is something I've taken for granted. That being said, even if the failure rate is 5% (which would be wildly high and causing panic with GM/Tremec), that still would mean 95% of people don't have any issues. Was a gamble I glad I took so far.

 

With the total scale of failures it is a very very small percentage that fail. We are talking a few percent on a mass produced car. You may think it is a bigger deal because most of the people who post on here are having some kind of issue looking for a solutions with various problems, you are not hearing from the 97,000 owners with zero problems.....

 

I struggled and researched for a long time about buying a c8. I am going for it although my judgment tells me to wait another year. I have not been able to really get any information on DCT issues from fellow members. No one can even tell me what material is in the contaminated filters- is it clutch material; gasket sealer, metal shavings?? Also not used to having dealer mechanics tearing into my cars- I guess they call them techs now. And then I started researching extended warranties and in regards to these issues not sure about how the “fine print” reads. i don’t think anyone is going to disclose any useful informations right now. It is a very cool car and I want it!!

 

It is a complicated gearbox and will take a little time to iron out the bugs. I'm sure it will be resolved.

 

Any DCT problems for the first 5 years would be handled the same and are covered whether you got no additional warranty, the limited warranty extension, or a service contract. A good service contract (i.e., the Chevrolet Platinum Protection Plan) would cover most DCT problems after the first 5 years are up.

 

Because they didn’t study?

 

so is everyone in agreement that all aspects of the dual clutch are covered in the 3yr/36 and the 5yr/60 powertrain warranty that comes with the car? That would be reassuring! That platinum one you can by I am not so sure it’s completely covered.

 

Why do DCTs fail? I would challenge anyone on the forum to study how a DCT truly works. Not just the general idea, but to consume the whole process of a simple gear change from point a-b and what it takes to make a simple transition happen in the broad spectrum of things. The amount of precision, pressure, oiling, and tolerances are mind-blowing. To say a few won't fail is denying the laws of the universe.

 

^^^
FWIW, don't think we have seen "failures" of the type that have been caused by how the DCT operates. It shifts basically like my two manual C7 M7s and all my 5 prior standard shift Vettes where I pulled on a lever. In fact for those who want to follow what IMO is far more mechanically complex is what the synchronizers have to do with every shift in a standard transmission. The C8 DCT uses the same triple synchro cones as gear ratios change as my Tremec C7 M7s. They actually have to backup synchronizer rings just slightly! Fortunately in the C8 they have more time than in my C7s BECAUSE the next gear is shifting in position when the group of the other 4 gears are working! Although, I still think about what must be happening when I'm braking hard in Track and it downshifts through two gears while rev matching much faster than I could stir my C7 stick and operate the clutch:

Nope, the C8 DCT failures reported are not related to operation. Leaking cases, valve bodies even clogged valves and passages are not causing mechanical type failures (or at least that is not what is being reported on the Forum.) Why? One reason in addition to design was outlined in a long forum post by a trans tech who had worked on 50+ C8 DCTs. He related what was found in transmission that had the 2 extra quarts of fluid and those that did not. He said there are over 100 CELs that can generate from the many sensors that monitor shift fork movement etc and several critical pressure areas. In fact throughout his long post he said a number of time it's NOT necessary to install the extra 2 quarts of fluid UNLESS Tracking. The DCT has 3 pressure sensors that will shut the system down if low pressure is detected in any of the 3 critical areas! So even clogged passages, valves or actuators trip a CEL and shut down before mechanical damages occur.

 

idk Phil.

A transmission "issue" is more like the A8 shudder which didn't strand you lol.

I would say this DCT has a better success rate than I ever imagined. It only sucks when you have one that falls into the failure category and those people couldn't care less that whoevers DCT is "fine".

 

There are A8s that never could get rid of the shudder, if a flush cleans some grit out and the DCT performs perfectly after, is that a failed transmission?

 

I probably should have been clearer that any internal DCT problems would be covered by the powertrain warranty. External DCT problems (i.e., computer, wiring, etc.) would only be covered under the B2B warranty. If you want coverage for external DCT problems beyond 3yr/36k then you need a warranty extension or service contract.

 

The valve body and solenoids should be part of the 5/60 though.

 

I think this really needs to be figured out warranty wise. We could easily be paying for all this complex stuff going on with the dual clutch that no one seems to understand in 3 years. I think the language is murky in the platinum plan. Any attorney types that could clarify?

 

I don't think it's too bad, the case and all internal parts are covered and that includes the valve body, solenoids, gears, shafts, shift forks, etc. A TCM and external wiring isn't part of the DCT and if the TCM makes it 3/36, it will probably go the life of the DCT. Wires don't just go bad so that's not of much concern. None of this with cost me any sleep.

 

The DCT is turning out to be like GMs other little beauty the A8. IMO it has nothing to do with it being a DCT and everything to do with it being a GM designed DCT if you catch my drift.

 

^^^^
Hmm, BUT it's NOT like the A8 "slushbox," which was GMs design and build. It's designed and built by Tremec, like my rock solid Tremec M7s in my two C7s! In fact it's much more like my M7s by far than the "slushbox" A8! It has constant mesh gears, synchromesh cones and other parts as well as shift forks. Lots of them.

The shift forks are activated by hydraulic devices instead of my hand stirring a stick!

Yep you're "drifting" out to sea with that comment!

 

The thing is just so complex. You have the clutches, trans,differential all spinning around in the same oil along with all kinds sensors, computers. I just hope I can figure out a warranty that truly covers all this for 5 years.

 

Below is a link to the 2020 warranty, I expect the newer cars to be the same:
https://www.chevrolet.com/content/da...Assistance.pdf
Personally, I'm not that concerned with any external DCT components that aren't covered by the powertrain warranty.