General Motors and Allison Transmission share a history that goes back to 1928, when the brand was known as Allison Engineering Company. GM pairs the Allison 10-speed with its Duramax diesel and gas-powered HD pickup trucks, such as the 2025 Chevrolet Silverado 2500 HD Trail Boss.
For a time, Allison Transmission was part of General Motors, but that ended when GM sold Allison in 2007. Beginning in 2020, GM HD pickup trucks have used an Allison-branded transmission that is produced by General Motors. That arrangement was working until the licensing agreement between GM and Allison Transmission, set to expire on December 31, 2025, wasn't renewed.
Current HD GM pickups, including Silverado and Sierra 2500/3500 models, use the 10L1000 Allison-branded automatic transmission built by GM. While the transmission isn't actually manufactured by Allison Transmission, its design is checked and validated by Allison before the Allison branding is applied to the trucks or any GM websites and promotional material. That'll change going into 2026.
Due to the expiring license agreement with Allison Transmission, GMC Sierra and Chevy Silverado HD gas and diesel pickups produced after December of 2025 will no longer be equipped with Allison-branded transmissions. The creation of new marketing materials with Allison badging is set to cease at the same time, but dealers are allowed to continue to use existing Allison branding until June 29, 2026. While used trucks are not affected, new trucks left on dealer lots must be retrofitted with new badging.
Car and Driver says, "Not only will GM stop slapping Allison badges on its trucks, but next year the company will retroactively hunt down any unsold Allison-badged trucks and debrand them." Essentially, while the marketing and badging will change in 2026, the transmission in HD GM pickups is staying the same for now.
With all that happening at the end of June 2026, it could be a good time to shop for a HD GM pickup equipped with an Allison-branded transmission. Hopefully, dealers will be willing to make deals rather than have to re-badge the trucks on their lots.