path 31 that lies in the common plane defined by the longitudinal shaft axes x 1 and x 2 the guide path 31 extends from a point 33 that is radially most distal from the axis x 1 at an axially proximal end 35 of the boss 30 to a point 37 that is radially most proximal to the axis x 1 at an axially distal end 39 of the boss 30 the terms axially proximal and axially distal are herein used in relation to distances from the isolator mechanism i the terms radially proximal and radially distal are herein used in relation to distances from their longitudinal axes of origin x 1 and x 2 the guide path 31 is also bounded between a pair of limiting axes 43 and 47 parallel to the shaft axis x 1 one limiting axis 43 extends through the radially most distal point 33 of the boss 30 and the other limiting axis 47 extends through the most proximal end point 37 of the boss 30 in the assembly 10 shown the guide path 31 extends downwardly from the radially most distal point 33 to the radially most proximal point 37 in a straight line path 31 and at an angle 49 as shown the radial distance 53 from the shaft axis x 1 to the radially most distal point 33 is greater than the radial distance 57 from the shaft axis x 1 to the radially most proximal point 37 by a distance 59 the other extension 60 has a boss 70 defining another guide path 71 that lies in the common plane defined by the shaft axes x 1 and x 2 as shown.