Regarding the increasing demand in seal lifetime and energy efficiency, a detailed microscopic simulation is necessary—as an addition to experimental investigations—to better understand and improve radial shaft seals. For this purpose, typically thermoelastohydrodynamic lubrication (TEHL) simulations are used. The published models range from rather simple elastohydrodynamic lubrication (EHL) models to very sophisticated TEHL models. Only very few models take into account the roughness or microstructure of both contact surfaces, though, since this would require the consideration of transient effects. In this article, a transient TEHL model for the contact of radial shaft seals is presented. Studies of the sealing contact are conducted, and the possibility of investigating shaft microstructuring is shown.