A global approach coupling experiments and numerical modeling is proposed to enhance crack prediction. Fretting tests have been conducted under conditions leading to crack formation. Three dimensional crack shapes have been reconstructed from metallographic cross-sections and described with level set functions. They are then used as input data in 3D two-scale X-FEM model detailed in this paper. Frictional contact conditions holding between the crack faces are accounting for. The methodology developed to describe those contact conditions at the pertinent scale is detailed. A 3D fretting fatigue test is modeled to illustrate the coupling between experiments and numerical modeling.