The rotary cement kiln forms a major part of any cement works. The kiln is a large cylindrical structure where the raw materials are brought together and heated to form clinker, the base material of cement. To ensure production plant reliability and product quality an understanding and evaluation of the kiln design parameters is of paramount importance. This paper presents a solution for evaluating the mechanical strength of the shims, vital components in the drive system. These parts transmit the rotational drive to the kiln drum, and are subject to large mechanical and thermal stresses. The results of this study enable a reliable plan for preventive maintenance of the kiln furnaces to be developed. The methodology employed detects the mechanical and thermal stresses distributed on the surface of the shim while the working cycle are active, and uses both mechanical theory and numerical simulation by the Finite Elements Method (FEM) under the ANSYS software. The numerical results provide an authoritative guide to the accurate prediction of the optimal preventative maintenance interval for the rotary cement kilns drive element.