Frame alignment is carried out by means of a special tool, namely a stack for restoring the geometry of the car body. The car body is a complex spatial structure that cannot be reconstructed based on visual assessment alone. The stack has the following principle of operation: the body is rigidly fixed on the stack platform, diagnostics of the displacement of the body's control points is carried out, after which the fasteners are installed that provide the ability to direct the force along three coordinate axes. After that, the power devices are connected, which develop a constant force in the corresponding directions of the body, under the supervision of the operator. The work is completed once the body geometry is restored.