Abstract This paper presents the detection of failure in gears using, as a statistical indicator, the Root Mean Square value from the vibration residual signal. Models for three double stage gearboxes are considered on the analysis. The gear models are designed with different modules in order to preserve geometrical resemblance. This research shows the variation on gear mesh stiffness for different amounts of damage. This paper also describes the development of a model to simulate the vibration response from the double stage gearbox for conditions with and without failure. The variation on time of the gear mesh stiffness is taken into account on the dynamic simulation, and damping coefficient is considered proportional to gear mesh stiffness. Results obtained from dynamic simulation for both good state and with failure teeth are in accordance with the results reported on literature. ----------Keywords: Gear mesh stiffness, residual signal, breakage of tooth, dynamic response Resumen Este articulo utiliza el valor RMS de la senal residual de vibracion como indicador estadistico que permita detectar la falla en ruedas dentadas. En el analisis se consideran tres modelos de caja de engranajes de doble