The unpredictable power fluctuation due to severe heating has been demonstrated to be a critical bottleneck technique restricting the application of magnetorheological (MR) clutches in vehicle industry. The aim of this study is to introduce a low-cost transient simulation approach for evaluating the heat build-up and dissipation of a liquid-cooled MR vehicle clutch. This paper firstly performs a detailed description of the developed MR clutch in terms of operation principle, material selection and configuration. Subsequently, transient temperature simulations are carried out under various conditions to reveal the distribution, variation and impact factors of the transient temperature field. Following these, an experimental setup is established for heating tests of the clutch prototype. Experimental results concerning the temperature variation of magnetorheological fluids and the maximum allowable transient slip power of the clutch prototype are presented, which in return verify the correctness and feasibility of the simulation.