6-Speed Automatic (DISC) No longer available as standard equipment as of January 16, 2019.
8-Speed TorqueFlite Automatic (DFD)
8-Speed TorqueFlite Automatic (DFL)
8-Speed TorqueFlite Auto
6-Speed Automatic
Transmission, 6-speed automatic, heavy-duty electronically controlled with overdrive and tow/haul mode. Includes Cruise Grade Braking and Powertrain Grade Braking (Requires (L96) Vortec 6.0L V8 SFI engine or (LC8) 6.0L V8 SFI Gaseous CNG/LPG capable engine.)
Cooling, auxiliary external transmission oil cooler