Automotive power window mechanism failure initiated by overload

Due to its nature of usage, typically automotive power window mechanisms fail due to fatigue. However, many of them could have been prevented because its initial crack is caused by overload. This paper outlines simplified manufacturing process and common failures of the mechanism. It also discusses about representative after market failures. Of the hundreds of after market returned products, representative ones were selected for metallurgical evaluation. Combined with comparison with newly manufactured product, a case study was performed. It was concluded that the failure was due to overload although the crack propagation was through fatigue loading as the mechanism was installed and used.