  Aims. The prototypical microquasar GRS 1758-258 exhibits large-scale
morphological changes in radio maps over time which have been attributed to the
rise of instabilities. Here, we investigate whether these effects could be
attributed to jet precession instead. Methods.We used new and archival radio
maps to fit a kinematic jet precession model. The value of the parameters thus
obtained were analysed in order to get constraints on the physical properties
of the GRS 1758-258 system. Their consistency with different theories of the
origins for the jet precession, such as Lense-Thirring effect and tidal torques
induced by the secondary star, has previously been studied. Alternatively, we
also assessed the possibility that observations are compatible with eventual
jet instabilities. Results. The new radio data presented here confirm that the
large-scale radio morphology of GRS 1758-258 is changing over time. Our study
shows that the 18.48 day period could plausibly be ascribed to precession, thus
implying a reinterpretation of assumptions made for the orbital period to date.
However, the observed structural changes in radio jets cannot be easily
attributed to jet precession according to our analysis. In contrast, the growth
of instabilities certainly appears to be a more realistic explanation of these
effects.
