This document provides instructions for removing and installing the front cover and front gear group of a Caterpillar C6.6 engine. The removal procedure involves removing components like the crankshaft pulley and fan, then removing bolts and separating the front cover from the housing. Tools are used to lock components like the crankshaft, camshaft and fuel injection pump in position. The installation procedure specifies cleaning and inspecting parts, then installing components like the camshaft gear and idler gear in their original alignment positions using tools to lock parts in place. Torque specifications and cautions about containing fluids are also provided.