Transmission, gearbox and vehicle

A transmission comprising:

• a primary gear rotatable about a rotation axis and including primary teeth, where each primary tooth has a primary surface;
• a secondary gear rotatable about the rotation axis and including secondary teeth;
• an intermediate gear rotatable about the rotation axis and including intermediate teeth, where each of the intermediate teeth comprises a primary intermediate part having a primary intermediate surface and a secondary intermediate part having a secondary intermediate surface, where the primary intermediate part is axially offset from the secondary intermediate part with respect to the rotation axis, and where the intermediate gear is axially displaceable along the rotation axis between an engaged position where the primary surface contacts the primary intermediate surface in a contact region and the secondary intermediate surface contacts one of the secondary teeth, and a disengaged position;
• wherein in the engaged position, one primary tooth and one intermediate tooth form an overlap, radially inside the contact region with respect to the rotation axis and as seen along the rotation axis, for preventing the intermediate gear from being displaced from the engaged position to the disengaged position.