The article deals with the examination of the state of the ball track at the heavy machine ZP 6600/Z79. This kind of machines are located in Doly Bílina. Article presents results of material exams which were taken on given samples and it describes the progress and results of the numeric calculations for the state of tenseness. The material tests were realized in an external cooperation. The numeric simulation of the tenseness was made in the VÚHU a. s. on the 3D model of the contact by a method of the ultimate elements. The used method works with the ending parts at the bottom of part of the ball track when it touches the ball. To determine the internal and contact forces in the ball and the bottom part of the ball track we used the software called COSMOS/DesignStar ver. 6.0. The result was an evidence for the decision about the depth of the turned layer of the material in order to create a new groove of the bottom part of the ball track.