The aim of this research is the analysis of the effect of the modification of the base profile angles of x-zero gear drives for the TCA parameters. We analyze the normal stress, the normal deformation and the normal elastic strain on the connecting zone of the gear pairs. Based on the received results we create diagrams which show the fluctuation of the analyzed TCA parameters in the function of the changing of the selected parameter of the x-zero gear drives. After the analysis we determine the consequences and select the appropriate variant.