a housing 44 via intermediate bearing insert the pin 38 is connected to a connecting piece or knuckle 40 the sealing boot 12 is connected at end 15 to the housing 44 via a clamping ring 46 the end 18 of sealing boot 12 is connected to the pin 38 by a clamping ring 48 the clamping ring 48 may be omitted as discussed further below fig5 shows the knuckle 40 with a sealing boot facing surface 42 the slipping ring surface 22 is positioned on the surface 42 to form a seal between the slipping ring surface 22 and knuckle 40 based on a soft gripping material coating e g rubber at the surface 22 or by the use of a sticky material such or an adhesive e g contact glue the guiding groove 20 may be provided with a lubricant 66 as shown in fig6 a this may be supplied in a preassembled state with the lubricant 66 already in position the guide groove 20 may have an advantageous ratio of the width d of the opening 64 to the width d of the widened portion 23 with a sufficiently small dimension d the lubricant may be substantially retained in the space 23 even during shipping and handling further a film may be applied over the gap 64 during shipping and handling further according to an alternative embodiment according to fig6 b.