The azimuthal distributions of nucleons are studied for central [sup 40]Ar+[sup 51]V collisions from [ital E]/[ital A]=35 to 125 MeV based on a Boltzmann equation. We demonstrate that the contribution to azimuthal asymmetry from residue rotation decreases with incident energy and eventually vanishes at energies [ital E]/[ital A][ge]75 MeV. In contrast, the contribution from the directed transverse motion remains important throughout the energy range investigated. We show that the disappearance of rotation is mainly caused by the onset of multifragmentation for which the thermal instabilities appear to play a minor role.