High-speed machining is essential in the manufacturing field, and it involves the removal of material through rotational and translational tool motion. Existing methods used for simulating the thermomechanical behavior of spindle systems in machining require extensive calculations owing to the geometry complexity and thermomechanical properties. This article presents a simplified model of an angular contact ball bearing and a simulation method for predicting the thermomechanical behavior of a spindle system. A commercially available software, ANSYS, was used to analyze the coupled behavior. The Matrix27 element was adopted to substitute the stiffness/damping characteristics of the angular contact ball bearing. Validated values of the thermal contact conductance for the contact option were adjusted to match the measured thermal characteristics of angular contact ball bearings. Experimental measurements of the temperature and deformation of a spindle were used to verify the simulated results for several preload conditions.