The results of the 1999 GMRC research project Development of Advanced Crankshaft Condition Assessment Methods will be presented. The objective of the research is to determine the relationship between crankshaft web deflections, primary bending stresses in the web, and remaining predicted crankshaft life using linear elastic fracture mechanics models. A large number of typical crankshafts were analyzed using finite element models to determine bending stresses as a function of easily measured web deflection. Geometric similitude principles were then used to generalize these relationships. The fracture mechanics models then yield a predicted remaining life for the imposed cyclic stress amplitudes. The results of the project will be incorporated into a Windows software program for transfer of the technology to the industry.