Pallet transport apparatus for transporting pallets within a rack installation, which is oriented orthogonally with a longitudinal direction (x), a transverse direction (z) and a vertical direction (y), along a travel route with longitudinal transport routes in the x direction and transverse transport routes in the z direction, comprising - a chassis with a pallet pickup unit, - an x travelling mechanism for moving in the longitudinal direction (x) with drivable left x wheel units (22.1) and right x wheel units (22.2) which are arranged laterally on the left and right spaced apart in the x direction, - a z travelling mechanism for moving in the transverse direction (z) with drivable, spaced-apart, left z wheel units (32.1) and right z wheel units (32.2) which are arranged laterally on the left and right, - travel drive assemblies for the wheel units (22, 32), - wherein there is a first travel drive assembly and a second travel drive assembly, characterized in that - there is a lifting drive assembly which activates either an X lifting device or a z lifting device, as a result of which the x or z wheel units (22, 32) can be brought into contact with the travel route depending on the x or z travel direction, - wherein the second travel drive assembly is coupled in each case in terms of drive by means of a coupling device to left x wheel units (22.1) or left z wheel units (32.2) and the first travel drive assembly to right x wheel units (22.2) or right z wheel units (32.1) of a side, and the coupling device permits the drive of the x wheel units or z wheel units by means of the first and second travel drive assembly (60, 70) at a different height level in the y direction, - the x wheel units of opposite wheel sides and the z wheel units of opposite wheel sides can be activated differently by the first and second travel drive assembly (60, 70) such that a tank drive is present. - a chassis with a pallet pickup unit, - an x travelling mechanism for moving in the longitudinal direction (x) with drivable left x wheel units (22.1) and right x wheel units (22.2) which are arranged laterally on the left and right spaced apart in the x direction, - a z travelling mechanism for moving in the transverse direction (z) with drivable, spaced-apart, left z wheel units (32.1) and right z wheel units (32.2) which are arranged laterally on the left and right, - travel drive assemblies for the wheel units (22, 32), - wherein there is a first travel drive assembly and a second travel drive assembly, characterized in that - there is a lifting drive assembly which activates either an X lifting device or a z lifting device, as a result of which the x or z wheel units (22, 32) can be brought into contact with the travel route depending on the x or z travel direction, - wherein the second travel drive assembly is coupled in each case in terms of drive by means of a coupling device to left x wheel units (22.1) or left z wheel units (32.2) and the first travel drive assembly to right x wheel units (22.2) or right z wheel units (32.1) of a side, and the coupling device permits the drive of the x wheel units or z wheel units by means of the first and second travel drive assembly (60, 70) at a different height level in the y direction, - the x wheel units of opposite wheel sides and the z wheel units of opposite wheel sides can be activated differently by the first and second travel drive assembly (60, 70) such that a tank drive is present.