This document provides instructions for removing and installing the main bearings on the crankshaft of a Caterpillar C7.1 engine. It outlines the required tools and gives step-by-step instructions for removing each main bearing cap and shell. It also provides instructions for cleaning, inspecting, lubricating, and installing the main bearing shells and caps to ensure the correct crankshaft end play. Proper cleaning, lubrication, and torque procedures are emphasized to prevent damage and wear.