General Motors May Face Class-Action Lawsuit Over Defective 8-Speed Transmissions Models affected include the Chevrolet Silverado and Colorado, as well as the GMC Sierra and Canyon The filed class-action lawsuit affects the Chevrolet Silverado as well as the GMC Sierra. Plaintiffs in the lawsuit allege General Motors’ 8-speed transmissions are defective. Certain Chevrolet, Cadillac and... Continue Reading →