What the Lawsuits Allege
The litigation centers on General Motors Hydra-Matic 8L90 and 8L45 eight-speed automatic transmissions installed in a wide range of Chevrolet, GMC, and Cadillac vehicles built roughly between 2015 and March 1, 2019. Owners allege the transmissions shudder and shake in higher gears and hesitate, lurch, or harshly engage in lower gears, with the problems often persisting even after repair attempts. Affected models named in the cases include the Silverado, Sierra, Colorado, Canyon, Corvette, Camaro, and several Cadillac and Yukon variants.
The plaintiffs allege that GM knew about the defect before selling the vehicles and did not adequately disclose it, and that dealers were at times told harsh shifting was normal. GM has disputed the claims, arguing among other things that most owners never experienced a problem. These are allegations that have not been resolved by a final judgment on the merits.
The 2025 Ruling That Changed Everything
The most important recent development is procedural. In the lead case, Speerly v. General Motors, a federal district court had allowed owners to proceed as a class. On June 27, 2025, the full Sixth Circuit Court of Appeals, sitting en banc, reversed that decision by a 9 to 7 vote, finding too many differences among the roughly 800,000 vehicle owners to justify resolving their claims as a single class. The practical effect is that the class was decertified.
Decertification does not mean the claims were found meritless; it means owners can no longer pursue them as a group in that case. Anyone who still wants to pursue a claim would generally have to do so individually. A companion case, sometimes referred to as the Ulrich action, separately survived a motion to dismiss in early 2025, so litigation activity continues even as the class structure has changed.
What This Means for Owners
For owners, the headline is that there is currently no class to join and no settlement fund to claim from in connection with the decertified case. That is a significant change from the position when the case had class status, and it raises the practical bar for any individual seeking compensation.
Owners who believe their vehicle is affected may still have individual options depending on their state, their warranty, their repair history, and applicable lemon laws or consumer-protection statutes. Because those options are fact-specific and deadline-sensitive, the realistic path is an individual assessment rather than waiting for a class recovery that, as the case now stands, is not on the table.
How to Get Legal Help
The class was decertified in 2025, so there is no class to join and no settlement fund. Affected owners who want to pursue a claim would now do so individually, and a consultation with a lemon-law or auto-defect attorney about your specific vehicle and repair history is the practical next step.
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GM Transmission Lawsuit: Where the 8-Speed Shudder Cases Stand: Frequently Asked Questions
Answers to the most common questions about this case and your legal options.
Which transmissions are involved in the GM lawsuit?
The GM Hydra-Matic 8L90 and 8L45 eight-speed automatic transmissions, installed in numerous Chevrolet, GMC, and Cadillac vehicles built roughly from 2015 to March 1, 2019, including the Silverado, Sierra, Colorado, Corvette, Camaro, and several Cadillac and Yukon models.
What do owners allege?
That the transmissions shudder and shake in higher gears and hesitate, lurch, or harshly engage in lower gears, often even after repairs, and that GM knew of the defect and did not adequately disclose it. GM disputes the claims, and they have not been resolved on the merits.
Is there a GM transmission class action I can join?
Not as the case now stands. In June 2025, the full Sixth Circuit decertified the class in the lead case, finding too many differences among owners. There is currently no class to join and no settlement fund from that case.
Did decertification mean GM won?
Not on the merits. Decertification means owners cannot pursue the claims as a single group in that case, not that the allegations were found to be false. Owners would generally have to pursue individual claims instead.
Can I still get compensation?
Possibly, through an individual claim, depending on your state, warranty, repair history, and applicable lemon or consumer-protection laws. Because these options are fact-specific and deadline-sensitive, an individual legal assessment is the practical route.