The haul truck is one of the main tools in the mining business. The function of tools to moving mining materials to refining and stacking, to making of haul truck became one of very large role in supporting the production quantity of mining companies. In mining trucks / haul trucks, the existing driving components are the engine, torque converter, transmission, differential, the final drive that is synergized, so that the performance of the haul truck is able to operate according to its carrying capacity. One of the main components is the transmission system to adjust the speed of the haul truck. PT XYZ is a mining company that entrusts maintenance and repair of heavy equipment at PT XXX with a Maintenance And Repair Contract. PT XXX is obliged to maintain the life of the component in accordance with the budget agreed by both parties to avoid losses. PT XXX must be able to return the transmission age from the replacement data that has been carried out less than the target age of replacement, so that based on the calculation, the losses to be experienced in the amount of US $ 1,800,000 can be avoided.

Keywords : DMAIC, Haul Truck Transmission, Maintenance.