The Mack Magnum was a B Double and Single application Prime Mover manufactured by Mack Trucks Australia, a division of AB Volvo. It consisted of a Renault Magnum cab and chassis, with an all American Drive line including a Roadranger 18 speed transmission and had either Rockwell or Dana drive axles. Although a 454 hp Mack engine was an option. This truck was not "replaced" by the Mack/Renault Quantum in fact they were sold alongside each other one being a premium heavy duty truck the other the smaller lighter less expensive model.Unfortunately the Magnum was plagued with electrical problems and part availability problems and thus its popularity waned quickly in Australia and was removed from Mack Australia's lineup after only 2 years never to return.