Abstract: A vehicle anti-theft device comprising a gear shift lock and an ancillary vehicle anti-theft device which is operated automatically by operation of the gear shift lock.

Abstract: A pin tumbler lock comprises a cylindrical shell, a plug fitted within the shell, and rotatable by key means. The plug has first bores for receiving first pin tumblers. The first bores are substantially normal to the axis of the plug. The shell has second bores for receiving second pin tumblers therein. The second bores are aligned with first bore. First and second pin tumblers are located in bores. The second pin tumblers are forced by a spring into the aligned first bores to thereby prevent rotation of the plug. The first and second pin tumblers have substantially mating surfaces at respective ends providing contact along their entire length. The plug includes two grooves in a plane normal to the axis of the plug along its periphery, one groove on each side adjacent to first bores, thereby providing a non-linear shear line between the plug and the shell.