The research presented in this paper aims to determine the influence of longitudinal gradients on the behavior of fastening systems of railway turnouts. This influence will be assessed through a case study in line No.3 of Greater Cairo metro network where 1 in 8 crossover has been installed in 2 % longitudinal slope. It has been observed that severe wear induced in the outer lead rail is out of tolerance in a short period after installation. Thus, the fastener steel clips on that rail have been damaged. Therefore, a sequence of analysis has been carried out in this paper to identify the causes of damaging of the clips. Clip`s material has been tested to determine its chemical composition; then stereoscopic photos of fracture surface of the clip (X8) have been taken. The vertical and transversal wheel loads of the wagons affecting the lead rail fastening system have been simulated using ANSYS software, thus results of the simulation have been analyzed in detail. Finally, a conclusion on the mechanical behavior of turnouts, a recommendation to minimize rail wear and to eliminate clips damaging have been introduced.