The paper presents the procedure for determining the force transmission index (T) for the Assur structural group 122 (in two variants) involved in the formation of mechanisms driven by linear motors. In the case of variant 122a, the index T is a function of two variables, which represent the main configuration parameters. This paper outlines the design method for the admissible domain of these parameters in a planar coordinate system. In the case of variant 122b, the index T is a function of a single variable, so the admissible range is defined between two values along an axis. As a case study, the method is presented for addressing a hydraulically actuated mechanism of a front loader. This mechanism includes this group in both variants as well as another Assur group of type 022.