A selector lever (1) that comprises a shaft (2) rotatably attached to a pivot (4) and arranged between two detent plates (8,10), each of the detent plates (8,10) having a plurality of slots (9,11) arranged for receiving a detent pin (12,13) located on the shaft (2). Each of the plurality of slots (9,11) on each of the two detent plates (8,10) is defined by a radial depth (D1,D2). One or more of the plurality of slots (9,11) is a failure detection slot (16,17) having an extended radial depth (E1,E2). When one of the detent pins (12,13) has failed, the opposing detent pin (12,13) is allowed to travel into the extended radial depth (E1,E2) when placed in the failure detection slot (16,17). This action reveals a failure indicator (18), providing a visual indication that one of the detent pins (12,13) has failed.