This tool instantly locates TDC (top dead center) on all Ford 4.6, 5.4 & 5.0 Coyote engines. It can also be used for 4.6, 5.4/5.8 engines to locate the crankshaft when installing timing chains. Tool slides over crankshaft and other end locates on timing cover dowel. (Timing cover must be removed to use this tool)