A torsional dynamic vibration absorber for a crankshaft, which consist of a vibroisolating rubber component and a moment of inertia, is used at relatively high temperature and frequency. It is important to analyze the steady-state response of such a system. The most simplified model consists of shear loading rubber isolator and a mass. We have already suggested an analytical method of the system for which mechanical nonlinearity and heat generation have been taken into consideration. The validity of it has been examined by comparing analytical results directly with experimental ones. In this paper, we give more detailed consideration and clarify the mechanism of the response. The system can be characterized as a system which couples the mechanical nonlinearity, depending on temperature and internal heat generation. As a result, we can derive again the analytical method in the previous report.