Continue investigations into stress relaxation of the screw-nut system at low temperature. Continue reproduction trials. Identify the cases of occurrence of these relaxations. Participate in the understanding and explanation of this phenomenon. Search for technical solutions (treatment, coating, etc.) thanks to the support of our laboratory and our suppliers in order to: Reduce wear phenomena. Stabilize cold efficiencies. Study a new screw-nut system lubricated by grease (instead of brake oil).