An axle mounted on a vehicle chassis includes a central box section, a first support arm connected to a first wheel and slideably mounted inside the central box section, and a second support arm connected to a second wheel and capable of longitudinal translational movement inside the first support arm, a guiding box section fixed to the central box section, including a rectangular tube and defining an external annular volume included between the central box section and the tube, and an internal volume included inside the tube, the first support arm being housed inside the external annular volume and able to be guided by the guiding box section along a first longitudinal translational path, the second support arm being housed inside the internal volume and able to be guided by the guiding box section on a second longitudinal translational path. A vehicle equipped with such an axle is described.