Rigid-body resonances used to be the only known vibration phenomena to occur in washing machines. However, lately there have been unexpected incidences of excessive, self-destructive vibrations. It is not clear how these incidents can be explained and reliably prevented. It is presumed that design changes evoke or shift vibrational phenomena which did not occur in the operating speed range of previous machines. Rotordynamic theories might be a suitable explanatory approach for these effects. However, since these effects have yet not been an issue, rotordynamic theories have never been applied to washing machines, even though they are obviously a rotor system and effects are well known for other applications. This paper investigates and highlights rotordynamic effects in frontloaders with a horizontal axis of rotation. To do so, a numerical multi-body model is utilized for dynamical analysis. Potential causes for rotordynamic effects in washing machines are discussed and included in the model. Numerical analyses of eigenvalues and transient displacements show several rotordynamic effects, their rough speeds and their dependency of different parameters. It is discussed how likely each effect is to shift into the operating speed range because of design changes, and thus how likely it is to become a threat. This gives a supplemented overview of the dynamic behavior of washing machines.