Many features commonly exhibited by canonical glass-formers can also be found in systems exhibiting translational long-range order. Orientationally disordered-crystals (or plastic-crystal phases) which show a long-range lattice formed by the molecule centers of mass whereas molecular orientations are randomized are one of such categories. Some examples of such materials are the monoclinic low temperature phases of CBrnCl4-n molecules (n= 0, 1, 2), the low-temperature phases of some adamantane derivatives, or some benzene derivatives. In this latter case, disorder originates from different occupancies of some atoms at different sites. Here we propose to carry out a neutron study on the dynamical processes taking place in the disordered monoclinic phase of tetrachloromethylxylene, TCMX (C6Cl4(CH3)2).