Experiments have been carried out on the Joint European Torus (JET) tokamak to determine the diffusive and convective momentum transport. Torque, injected by neutral beams, was modulated to create a periodic perturbation in the toroidal rotation velocity. Novel transport analysis shows the magnitude and profile shape of the momentum diffusivity is similar to those of the ion heat diffusivity. A significant inward momentum pinch, up to 20m/s, has been found. Both results are consistent with recent developments in momentum transport theory and gyro-kinetic simulations. This evidence is complemented in plasmas with internal transport barriers.