it unnecessary to make excessive changes in the shape of the cross sections of the sections which would result in an excessive difference of pressures and pressure distribution and also makes it possible to maintain at all times a clear indication of the position required for coupling together the two tubular members of the telescopic shaft formed by said sections together with a manifest indication of the angular position of each of the tubular members relative to the corresponding socket which is to receive one end of each of the tubular members in a telescopic cardan shaft in which the forks of the cardan joints must have a specific position with respect to each other as is clearly shown in fig7 in which the number 101 indicates an outer tubular member and 103 indicates an inner tubular member see also fig3 to 6 of a cardan shaft to which are to be connected respectively the component 105a of a terminal cardan joint 105 and a component 107a of a cardan joint 107 joined to the opposite end of the telescopic shaft the cardan joint 105 is engaged with the tubular member 101 and the cardan joint 107 is engaged with the tubular member 103 and these members must be positioned in a very precise angular disposition in the sockets formed by the two components 105a and 107a respectively for correct operation of the telescopic cardan shaft as a whole in the production of a telescopic shaft it is possible to make the thickness of the outer tube slightly smaller than that of the inner tube owing to the larger dimensions of the cross section of the outer tube it is to be understood that the drawing shows only an.