Gear shift drum assembly for a shift device of a transmission unit, in particular for motor vehicles, with a gear shift drum body which is rotatable about a gear shift drum axis, with a first shift element, with a second shift element, wherein a first and at least a second shift contour (52a, 52b) are formed on the gear shift drum body and extend over 360 degrees of the circumferential portion of the gear shift drum body, wherein the first and second shift contour (52a, 52b) are formed in an axial and/or radial direction, wherein the first shift element engages with the first shift contour and the second shift element engages with the second shift contour in such a way that these are displaced by means of the corresponding shift contour in the axial direction of the gear shift drum body by rotation of the gear shift drum body, characterized in that the gear shift drum assembly has a shiftable coupling device, in that the first shift contour has an optional path, and in that the optional path has a form of an axially locally widened first shift contour in the gear shift drum body, in that the first and the second shift element (51a, 51b) can be coupled by way of the shiftable coupling device in such a way that an axial displacement of the second shift element onto the first shift element is effected for the purpose of shifting to a neutral gear position, which is assigned to the optional path, wherein the axial widening of the optional path extends over an angular range, wherein, in this angular range, the first shift element is shifted between a gear stage and a neutral position in the optional path and the second shift element is shifted between a gear stage and a neutral position. with a gear shift drum body which is rotatable about a gear shift drum axis, with a first shift element, with a second shift element, wherein a first and at least a second shift contour (52a, 52b) are formed on the gear shift drum body and extend over 360 degrees of the circumferential portion of the gear shift drum body, wherein the first and second shift contour (52a, 52b) are formed in an axial and/or radial direction, wherein the first shift element engages with the first shift contour and the second shift element engages with the second shift contour in such a way that these are displaced by means of the corresponding shift contour in the axial direction of the gear shift drum body by rotation of the gear shift drum body, characterized in that the gear shift drum assembly has a shiftable coupling device, in that the first shift contour has an optional path, and in that the optional path has a form of an axially locally widened first shift contour in the gear shift drum body, in that the first and the second shift element (51a, 51b) can be coupled by way of the shiftable coupling device in such a way that an axial displacement of the second shift element onto the first shift element is effected for the purpose of shifting to a neutral gear position, which is assigned to the optional path, wherein the axial widening of the optional path extends over an angular range, wherein, in this angular range, the first shift element is shifted between a gear stage and a neutral position in the optional path and the second shift element is shifted between a gear stage and a neutral position.