2020 Silverado 3.0 LM2 Engine/Trans Failure

Jake_Melvin1 · January 13, 2023

I have a 2020 RST with the 3.0 LM2 Duramax with 79k miles… the flywheel failed when I was driving down the highway and left me dead in the water.. I had it towed to the dealership 4 weeks ago and they called today and said the transmission and the engine needs to be replaced. Has anyone experienced this with their trucks? I never towed anything heavy and was religious with service.. luckily all covered under the 100k powertrain warranty…

64BAwagon · January 13, 2023

A new engine and trans under warranty ? I would call that a win.

I doubt that the dealer would even tell you if they knew what the cause was.

Everything on these trucks is designed and built by humans. Typically humans are sketchy and prone to unreliable behavior.

The only thing an engineer can guarantee is an eventual failure, glad youre still under warranty.

Jake_Melvin1 · January 14, 2023

Very true. I guess its a win, frustrating not having the truck for a few months though. Could be worse, could be paying for all this! Thanks for the reply.

seamus2154 · January 16, 2023

Flywheel failed?? It killed a motor and transmission?? Happy its covered, but any other details regarding?? They diagnosed or found a failed flywheel or just said they thought that?? 79K and getting a new drivetrain is a win.

Jake_Melvin1 · January 16, 2023

Hey Seamus - yes, that was the first call I got when they first took it apart. They said that the flywheel failed and that it also banged up the housing. Didn’t hear from them for 2 weeks and they called back and said the transmission was filled with metal so that was also getting replaced. He said the master tech is also starting to disassemble the engine but it’s looking like that will also get replaced.. truck showed no symptoms and was driving fine.

I’m trying to stay optimistic about the new drivetrain… curious how rear diff and transfer case look. I don’t know enough about these drivetrains to know if they’d be affected by this as well. Thanks for the response!

seamus2154 · January 17, 2023

Pretty unusual, but sounds like a defective flywheel let go and took out alot of stuff for them to be tearing into the motor also. If it rolled to a stop I will bet your rear diff is just fine. I'd be much happier with a crate motor and trans than anyone ripping into the motor and fixing something. The LM2 is literally their best drivetrain right now, and few big issues. New from Gm should be plug and play so to speak, and put this in your rear view mirror as its not a common issue. Good luck, keep us updated