The GM 8-speed automatic transmission that will be available in the all-new 2019 Silverado and Sierra has been improved over the unit in previous-generation trucks.
In a line buried deep within a previous announcement uncovered by GM Authority, Chevrolet states that the 8-speed Hydra-Matic in the 2019 Silverado features “enhancements designed to improve shift quality, as well as a new centrifugal pendulum absorber torque converter that reduces vibrations to improve smoothness.”
In prior-generation, K2 platform Silverado and Sierra, the GM 8-speed was often criticized for its jerky and unexpected shifting behavior that ultimately worsened the satisfaction of driving and/or riding in the pickup. Whether the improvements made to the 8-speed gearbox in the all-new T1 platform 2019 Sierra and Silverado will address these issues is unknown.
By comparison, the 8-speed automatic in the last-generation Silverado and Sierra is assigned RPO code M5U.
Both transmissions are electronically-controlled and feature overdrive, tow/haul mode, cruise grade braking and powertrain grade braking.