6-Speed Aisin HD 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 engine.)
Cooling, auxiliary external transmission oil cooler