A window operator and assembly method therefor wherein a stacked pull arm and gear are rotatably mounted on a bushing carried by a mounting base and the gear and pull arm are assembled to the mounting base with a controlled clearance independent of the tolerance of these components by use of a hardened metal bushing. The hardened metal bushing is forced into the deformable metal of the mounting base whatever distance is necessary to locate an exposed end of the bushing a fixed distance beyond the uppermost of said gear and pull arm and provide a surface against which a washer may be mounted and which overlies the pull arm and gear to hold the components in assembled relation with the controlled clearance.