General Motors and Allison Transmission have filed for divorce. GM sent a letter to the Chevrolet and GMC dealerships stating that the Allison Transmission licensing agreement expires on December 31, 2025 and that all Allison Transmission badges will be removed from new unsold trucks by June 29, 2026. Here’s everything we know. Let’s dig in.
There is no other good way to describe what’s going on other than a divorce filing. GM and Allison Transmission have been separate companies, the same company, and the separate companies before. Chevy and GMC pickup trucks have used Allison transmissions since 2001 models. It was a great partnership, until what happened in late 2018. GM announced that they will be placing an “Allison branded” 10-speed heavy duty transmission into their new generation 2020+ HD pickup trucks. The announcement included that these 10L1000 automatic transmission are built by GM, and the design is checked and validated by Allison Transmissions. Also, “Allison Transmissions” would be placed on all of these 2020+ pickup trucks.
The recent announcement, dated October 14, 2025, explains the licensing agreement expiration. You can see this letter here.
GM will stop putting “Allison Transmission” badges on their Chevy Silverado HD 2500 and 3500 (GMC Sierra HD) pickup trucks starting in December 2025. If dealers have any remaining inventory of 2025 and 2026 model HD trucks, GM will retrofit these trucks with new badges before June 29, 2026. This appears to be an aggressive timeline and a strong action.
We reached out to our contacts at General Motors for a confirmation, and this is what we received.
One of our contacts at a GM dealership in Colorado confirmed receiving the Oct 14th, 2025 letter as well.
All Chevy and GMC 2500 and 3500 heavy-duty pickup trucks are equipped with their 10L1000 automatic transmission. The Duramax turbo-diesel name will remain as well. We have not seen the new badges yet, but we expect it to focus on the 6.6L Duramax V8 diesel or the 6.6L gasoline V8 engines.
What do you think about this new development. Please let us know in the comments section below.
