General Motors And Allison Transmissions Are Divorcing Next Year
After more than two decades working together, General Motors and Allison Transmission are officially splitting up.
Key Points
- GM and Allison Transmission will officially end their heavy-duty truck partnership in 2026, concluding a collaboration that began with the Duramax diesel era in 2001.
- By June 29, 2026, GM must remove all Allison Transmission badges from unsold Silverado HD and Sierra HD trucks, marking the end of Allison branding on GM pickups.
- Since 2020, GM’s heavy-duty trucks have used an in-house 10-speed automatic transmission, developed with Ford, effectively replacing Allison-built gearboxes and rendering the partnership a branding exercise.
According to internal documents first published by TFL Truck, the companies’ long-running partnership on heavy-duty truck powertrains will formally end in January—bringing to a close a relationship that dates back to the early days of the Duramax diesel era.
Since 2001, Chevrolet Silverado HD and GMC Sierra HD pickups have worn “Allison Transmission” badges, a proud mark of durability and performance in the heavy-duty truck market—carrying almost as much cachet as Cummins, maybe more in some circles. Partnering with Allison, known for its expertise in heavy-duty commercial-grade gearboxes, gave GM a competitive edge in both towing and reliability.
But as of January 1, 2026, that partnership officially expires. By June 29, GM dealers will be required to remove all Allison badging from any unsold inventory, even if those trucks were built before the cutoff date. Once that happens, no GM pickup will legally be sold wearing the Allison nameplate again.
Unfortunately, the split has been a long time coming—GM’s introduction of its own 10-speed heavy-duty automatic transmission in 2020 effectively ended Allison’s physical involvement in the truck's development, though the branding continued.
The current transmission was developed internally, in collaboration with Ford, though Allison provided some validation input and consulting; Allison no longer built the actual gearboxes. The last five years of Allison branding was really little more than just a marketing exercise.
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An experienced automotive storyteller and accomplished photographer known for engaging and insightful content. Michael also brings a wealth of technical knowledge—he was part of the Ford GT program at Multimatic, oversaw a fleet of Audi TCR race cars, ziptied Lamborghini Super Trofeo cars back together, been over the wall during the Rolex 24, and worked in the intense world of IndyCar.
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