Abstract: A twist lock pivot pin is provided for rotatably connecting a lift arm of a cross arm window regulator mechanism for a vehicle window to a support panel. The lift arm has a non-circular through opening and the pivot pin, which is rotatably supported by the support panel, is provided with a complementary shaped non-circular head which is insertable through the non-circular opening in the lift arm. The head of the pivot pin is undercut to define a neck which engages a side surface of the non-circular opening in the lift arm when the pivot pin is rotated 75.degree. to cause sections of the head to overlie the lift arm to lock the lift arm to the support panel against movement axially of the pivot pin. A counterbalance spring then biases the neck of the pivot pin into engagement with the lift arm.