Providing the direct feedback of a manual transmission with the total convenience of an automatic, the new seven-speed MCT with AMG Speedshift is an all-new design available only in the new SL63 AMG. Featuring seven speeds, four shift modes and a double-clutching function, the MCT transmission offers impressive versatility and even faster shift times.At the heart of the new AMG Speedshift MCT seven-speed sports transmission is a new start-up clutch, which runs in an oil bath and replaces a conventional torque converter. Thanks to its low rotational mass, the start-up clutch helps the transmission respond instantaneously and dynamically with no slip.
Twin overhead camshafts in each cylinder bank open the 32 valves via bucket-type followers. In other words, instead of rocker arms, the cam lobes sweep across the flat top of the followers, which sit directly on top of the valve stems. This space-saving design provides a very stiff valve train that allows for large valve openings and dependable high-speed operation for maximum horsepower and torque. However, in contrast to racing engines, each bucket incorporates a hydraulic lifter that automatically maintains valve clearance, which allows for long service intervals and low costs.