GM is Getting Sued Over Recalled 10-Speed Automatic Transmissions

General Motors is once again facing legal trouble tied to its 10-speed automatic transmission, a gearbox that has spent the last several years building a reputation GM probably wishes it didn’t have.

A new class-action lawsuit filed in California claims the automaker knowingly continued selling vehicles equipped with the transmission despite being aware of ongoing defects and customer complaints. The case arrives after GM expanded an earlier recall covering full-size trucks and SUVs, along with the Cadillac CT4, CT5, CT6, and Chevrolet Camaro, over concerns that transmission failures could momentarily lock the rear wheels while driving.

Things aren't going great for GM on the full-size front, with both transmission and engine problems showing up on the automaker's bread and butter vehicles.

Filed in the U.S. District Court for the Northern District of California, the complaint accuses GM of violating both state and federal consumer protection laws by failing to properly disclose transmission-related problems to buyers and lessees. The plaintiffs allege the company continued selling affected Chevrolet, GMC, and Cadillac models while already aware of issues involving harsh shifting, hesitation, gear engagement problems, and sudden drivetrain locking.

The lawsuit points to previous technical service bulletins and recalls issued by GM involving the 10-speed automatic. Plaintiffs argue that those actions acknowledged portions of the problem without addressing what they allege as a design defect. According to the filing, owners were left facing expensive repairs, repeated dealership visits, and uncertain long-term reliability.

At the center of all this is GM’s 10L80 and related versions of the jointly developed 10-speed transmission, which first appeared as part of a collaboration between General Motors and Ford. On paper, the transmission made plenty of sense.

More gears theoretically allow better fuel economy, improved towing performance, and smoother acceleration by keeping the engine operating closer to its optimal power band. In practice, though, adding complexity also creates more opportunities for calibration issues, hydraulic faults, and wear problems that become noticeable once mileage starts climbing.

GM has not publicly commented on the lawsuit so far. The case remains in its early stages, and it could take months before a judge determines whether it will proceed formally as a class action. Plaintiffs are seeking compensation for repair costs and related damages, while also asking for changes to how GM markets or discloses information about vehicles equipped with the transmission.

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