Abstract: An improved gas flow diverter is provided, which includes a rotatably mounted diverter blade, a rotatably mounted turning vane assembly, a drive shaft adapted for receiving torque from a drive mechanism, and a toggle assembly, including a pair of toggle joints, mounted on the drive shaft and linked to the diverter blade and turning vane assembly. The improved construction of the gas flow diverter allows dependent synchronous rotation of the diverter blade and turning vane assembly.