Transmisión:Transmission, 10-speed automatic, electronically controlled with overdrive and tow/haul mode. Includes Cruise Grade Braking and Powertrain Grade Braking (Available on CK10543 4WD models equipped with (L84) 5.3L EcoTec3 V8 engine. Included and only available on CK10743 models, (LM2) Duramax 3.0L Turbo-Diesel I6 engine or (L87) 6.2L EcoTec3 V8 engine.)