Next year, heavy-duty GM trucks will lose their Allison badges, even though the transmissions themselves won't change.

The two brands have worked together for decades, but they couldn't reach an agreement to extend their longstanding licensing deal.

After more than two decades working together, General Motors and Allison Transmission are officially splitting up.

GM is taking the unprecedented step of removing some of the badging on its unsold trucks starting in 2026. Here's how GM ended up in this weird situation.