Tremec designed, manufactured parts in Mexico, where they based. They assembled the C8 DCT in a new facility in Michigan. GM had to cut a deal with the Canadian Auto Union to bring jobs back they eliminated. That is where they are assembled now with Tremec supplied parts. My "guess" Tremec had some issues with the assembly location in Michigan so was willing to forgo that labor cost and some profit. Also my guess, that last recall for a number of DCTs related to them finding some bolts in the DCT were not torqued properly and being replaced would be on GM's dime. Were they returned to Canada to be "fixed?" Don't know

I don't know the details of the Tremec supply agreement, but agree IF defects are related to assembly (as some early failures were attributed to shafts that were not cleaned properly) in Detroit, repair cost was surely on Tremec. Poor assembly now is on GM!

Not sure who is examining the returned transmissions? Do they go back to Tremec factory in Michigan where I believe they deal with other transmissions (they make to trucks, earthmoving equipment etc?) Would guess if they do a GM person is there to "help" decide who is responsible (push the blame to Tremec!)

SIDEBAR
When I built my street rod in 2000 the fellow who owned what was called "Custom Transmissions" built the race prepared TH400 with HD parts. His main business was repairing transmissions for all the car dealers. He told me they did not have enough volume to keep folks trained for repair. He even bought a Trans dyno so he could test a repaired trans. A few years later he opened up a new shop with 8 service bays and renamed it Dun-Right Automotive and Repair. He told me dealers were not getting enough transmissions on warranty for him to just specialize! I'm sure he would be happy to rebuild the DCT! He does others! Also just a question of time when failed parts, like other car parts, come from China etc.

 

Bottom line is we don't know what the issue is with the DCT. We also don't know where the bad ones go, who is repairing them or if the replacements are new or remanufactured.

 

Hopefully you will get your C8 back quickly and have many problem free miles .

 

Same here, no issues, 10K miles on our 2023 SR. Picked it up in Bowling Green and drove it to AZ, then to WA.
We are snowbirds so this is our repositioning ride.

 

It is interesting that the dealers do not take transmissions apart and attempt a repair. It is always "replace Trans".
Swap it for a new one.
That tells me that the trans is so complicated that GM does not want the dealer service technicians working on them.

It is a very complex machine and this is the first generation for GM. Yes, European car have had DCT for a few years and I would bet they had their share of problems.
Ten years from now we will look back and say; remember all of the problems they had with the first ones.

I worked for a truck manufacturer and I know it takes time to resolve new production problems and it never happens as fast as you expect.
So I am always looking at it from the manufacturer perspective. Easy for me to say because my car has been trouble free for 7000 miles.

 

^^^^
Hmm are they installing new or rebuilt?

My 2020 C8 DCT was perfect for 4 years as is my E-Ray for 6 months. IMO that is the vast majority. Yep a few have had pan leaks a dealer can fix. Early 2020's had some case casting porosity that was fixed late 2020. Don't hear much about weeping cases now.

As I said I don't know what Tremec's supply agreement says. I brought the subject up with our retiree Lunch group this week. We discussed the VP QA we hired from Bosh who tried to implement the auto industry supplier responsibility for failure. One attendee is my good friend who was our VP national accounts when I retired in 2000. He just retired at 67 and relayed a recent Tesla agreement for a product my former company where he was Senior VP was suppling aluminum welding wire. He said the purchasing agent was insisting their supply agreement be signed. It had a clause that said IF a weld cracked, the selling company was responsible for the repairs! He explained they can certify the wire chemistry BUT could not control the base material chemistry, welder workmanship etc. The purchasing person didn't care. It was several million annual sales but he rightfully held his ground.

Yep, IMO Tremec pays the repair cost for a unit failed in warrantee. For how long don't know. Expect those returned units are repaired, may be a simple solenoid that needed replacement. Nope they aren't just dumped in Lake Michigan to become fish habitat!

At some point there will an economic incentive for the free enterprise system to work when a customer pays. Trans repair folks will get parts from wherever and fix them. It's not a space shuttle. Two 4 speed transmissions with shift forks, sychro's in each gear etc. Hydraulic actuators moving the shift forks instead of a manual lever.