Abstract: An end cap for a windshield wiper motor housing includes a cylindrical shell and an end cap, the end cap being retained on the shell without fasteners. This is achieved by placing the end cap within the shell in a prestressed condition and forming supporting elements on one side of the end cap and holding elements on the other side of the end cap. The supporting and holding elements are axially spaced from each other by an amount less than the thickness of the material of the rim of the end cap so that the rim of the end cap in the finished configuration has a corrugated contom. The forces exerted on the holding and supporting elements by the elasticity of the end cap material effectively prevent the end cap from turning relative to the shell and makes the shell more shock resistant.