I am trying to find out what problems Ford Motor Company experienced with the CVT Automatic Gearbox that was used in the Focus C-Max between 2004-2005 and why they changed back to a standard type gear … A government lab has been doing long-term tests of many EV cars including 4 2013 C-max. They log all service and repairs. Three out of the four have required transmission replacement between 90k and 116k miles, with an average cost of around $4000. Other service has been negligible in comparison. IWY6.