In intermetallic alloys Re2Fe17 containing light lanthanides, it has been clearly established a close link between the MCE effect, the magneto-volume anomalies and the temperature dependence of the Fe magnetic moment, through combining magnetization measurements and neutron diffraction experiments. In order to get information in R2Fe17 powdered samples on the magnetoelastic coupling it will be necessary to investigate the phonon excitations in the paramagnetic phase averaged within the Brillouin zone. The temperature dependence of these excitations as well as the effect of the Rare Earth (contraction and exchange field strength) will provide deeper insights into the underlying magneto-structural mechanisms characterizing these intermetallics.