Fifth wheel, method for determining a load condition and/or a wear condition of a fifth wheel and method for upgrading a fifth wheel

A method for determining a load condition and/or a wear condition of a fifth wheel, comprising:

• providing a coupling plate configured to receive a journal element of the trailer;
• and
• providing a bearing block configured to the pivotable bear of the coupling plate about a horizontally extending pivot axis;
• providing at least one distance sensor which is configured to determine a distance with respect to a reference surface, the at least one distance sensor and/or the reference surface being part of the bearing block or arranged on the bearing block;
• sensing via the at least one distance sensor the distance with respect to the reference surface;
• and
• determining a current load condition and/or wear condition of the fifth wheel based on the determined distance and a selected stiffness model for the bearing block.