Toothed-shaft system comprising a toothed shaft and a functional element which can be, or is, fastened on the toothed shaft, wherein the toothed shaft has an outer toothing extending parallel to an axis of rotation of the toothed shaft, wherein the functional element has an inner toothing, and wherein the outer toothing of the toothed shaft and the inner toothing of the functional element can be made to engage, or do engage, one inside the other, wherein - one of the interengageable or interengaging toothings (11; 21) has first toothing gaps (11a; 21a*) and second toothing gaps (11b; 21b*), and - the other one of the interengageable or interengaging toothings (21; 11) has interference-fit-toothing teeth (21a; 11a*), wherein a clearance-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the first toothing gaps (11a; 21a*), and wherein an interference-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the second toothing gaps (11b; 21b*), and wherein a toothing-free portion is arranged and/or formed adjacent to the first and second toothing gaps (11a, 11b; 21a*, 21b*), characterized in that the first toothing gaps (11a; 21a*) and the second toothing gaps (11b; 21b*) are formed in a common toothing portion of the toothing (11; 21) and are distributed over the circumference of the latter (11; 21), wherein the toothing-free portion is arranged and/or formed adjacent to the common toothing portion of the toothing (11; 21), said common toothing portion being provided with the first and second toothing gaps (11a, 11b; 21a*, 21b*). - one of the interengageable or interengaging toothings (11; 21) has first toothing gaps (11a; 21a*) and second toothing gaps (11b; 21b*), and - the other one of the interengageable or interengaging toothings (21; 11) has interference-fit-toothing teeth (21a; 11a*), wherein a clearance-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the first toothing gaps (11a; 21a*), and wherein an interference-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the second toothing gaps (11b; 21b*), and wherein a toothing-free portion is arranged and/or formed adjacent to the first and second toothing gaps (11a, 11b; 21a*, 21b*), characterized in that the first toothing gaps (11a; 21a*) and the second toothing gaps (11b; 21b*) are formed in a common toothing portion of the toothing (11; 21) and are distributed over the circumference of the latter (11; 21), wherein the toothing-free portion is arranged and/or formed adjacent to the common toothing portion of the toothing (11; 21), said common toothing portion being provided with the first and second toothing gaps (11a, 11b; 21a*, 21b*). wherein a clearance-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the first toothing gaps (11a; 21a*), and wherein an interference-fit toothing can be, or is, formed by engagement of the interference-fit-toothing teeth (21a; 11a*) in the second toothing gaps (11b; 21b*), and wherein a toothing-free portion is arranged and/or formed adjacent to the first and second toothing gaps (11a, 11b; 21a*, 21b*), characterized in that the first toothing gaps (11a; 21a*) and the second toothing gaps (11b; 21b*) are formed in a common toothing portion of the toothing (11; 21) and are distributed over the circumference of the latter (11; 21), wherein the toothing-free portion is arranged and/or formed adjacent to the common toothing portion of the toothing (11; 21), said common toothing portion being provided with the first and second toothing gaps (11a, 11b; 21a*, 21b*).