GM Transmission Class Action: A Major Decertification Ruling

What the Lawsuit Alleges

The case, Speerly v. General Motors, alleges that certain 2015 to 2019 Chevrolet, GMC, and Cadillac vehicles equipped with GM Hydra-Matic 8L45 or 8L90 eight-speed automatic transmissions suffer from a design defect causing the vehicles to hesitate, then shake, shudder, jerk, or hard-shift both when changing gears and while accelerating in a single gear. Affected models named in the litigation include the Chevrolet Silverado, Colorado, Corvette, and Camaro, GMC Canyon, Sierra, and Yukon, and Cadillac CTS, CT6, ATS, ATS-V, and Escalade.

Plaintiffs allege the problem stems from friction surfaces, hydraulic systems, and gears inside the transmission and torque converter not functioning properly, circulating metal shavings that cause escalating damage over time, and that GM knew about the defect as early as 2014 but chose not to fix it broadly. The lawsuit claims GM internal engineers proposed a fix costing about 305 dollars per vehicle, an estimated 592 million dollars total, but that GM instead replaced the transmission only in a small number of unsold vehicles in certain states.

A Win, Then a Major Reversal

In March 2023, the federal district court certified 26 separate statewide classes covering the claims. In August 2024, a three-judge panel of the Sixth Circuit Court of Appeals affirmed that certification, a significant win for plaintiffs covering roughly 800,000 vehicles, including about 514,000 within the certified classes.

However, GM sought rehearing before the full appeals court, and in a rare move, the full Sixth Circuit voted to decertify the class action in 2025, reversing the panel decision. GM had argued that most class members never experienced transmission problems and therefore lacked standing to sue, and that too many individual differences existed among class members to justify a single group lawsuit. The ruling drew a pointed dissent from the original panel judge, who argued the decision created excessive barriers to class certification against national manufacturers.

Where the Case Stands Now

The decertification sends the litigation back to the federal district court in Detroit for further proceedings, meaning the case is not over, but it no longer has the certified class-wide status it previously had. This is a significant setback for the scale of relief plaintiffs had been pursuing, though it does not resolve the underlying factual allegations about the transmission defect itself.

Separately, a related case called Ulrich v. GM, covering additional states not part of the original certified classes, and a newer, distinct lawsuit concerning 10-speed transmissions in more recent GM vehicles, remain part of the broader landscape of GM transmission litigation. As of this update, no settlement has been reached in any of these matters.

How to Get Legal Help

If you own a GM vehicle experiencing transmission shuddering, jerking, or premature failure, note this litigation primarily concerns the 8L45 and 8L90 eight-speed automatic transmissions used in specific 2015 to 2019 Chevrolet, GMC, and Cadillac models, and a separate case exists over 10-speed transmissions in newer vehicles. Keep detailed repair records and consult an attorney, since class certification remains unsettled and individual options may still exist regardless of how the group case proceeds.

To follow any further developments, bookmark this page and subscribe to LawsuitWatch alerts.