Helical gears are subjected to contact fatigue loads, which may result in the damage of the gear teeth, for example by pitting-type failure. Microstructural features, mechanical properties and residual stresses have strong influence on the pitting resistance of the material. Case hardening, followed by shot peening processes, are usually carried out to produce a wear-resistant surface with compressive residual stresses established in the gear tooth surface region. This work aims to evaluate, by finite element analyses, the stress distribution through the gear teeth during the gear coupling. The results allow the evaluation of the stress components that may lead to the pitting failure, indicating the design variables that are important to improve the reliability of the gear