A joint assembly, comprising: a first joint member drivingly connected to at least a portion of a second joint member by a third joint member; wherein said second joint member has an outer surface, a first end portion, a second end portion and an intermediate portion interposed between said first and second end portions (436, 438) of said second joint member; wherein a shaft portion extends axially outboard from at least a portion of said outer surface of said intermediate portion of said second joint member; wherein a plurality of axially extending shaft portion splines circumferentially extend along at least a portion of said outer surface of said shaft portion of said second joint member; wherein said plurality of axially extending shaft portion splines of said shaft portion of said second joint member has a first end portion, a second end portion and an intermediate portion interposed between said first and second end portions (468, 470) of said plurality of axially extending shaft portion splines; wherein at least a portion of said second end portion of said plurality of axially extending shaft portion splines has a shaft portion installation aid having a first end, a second end and a transition portion interposed between said first and second ends (488, 490) of said shaft portion installation aid; wherein said first end to said transition portion of said shaft portion installation aid defines a first portion of said shaft portion installation aid; wherein said transition portion to said second end of said shaft portion installation aid defines a second portion of said shaft portion installation aid; and wherein said outermost diameter of said plurality of axially extending shaft portion splines of said first portion and/or said second portion of said shaft portion installation aid is defined by a radius R2 from a centerline CL1 of said joint assembly, wherein, in a cross sectional plane perpendicular to the axis of said shaft portion, said intermediate portion of said plurality of axially extending shaft portion splines has a substantially polygonal shape, and characterised in that, in a cross sectional plane perpendicular to the axis of said shaft portion, said outer surface of said plurality of axially extending shaft portion splines of said shaft portion installation aid has a continuous arcuate or curved shape that is defined by a plurality of radii. a first joint member drivingly connected to at least a portion of a second joint member by a third joint member; wherein said second joint member has an outer surface, a first end portion, a second end portion and an intermediate portion interposed between said first and second end portions (436, 438) of said second joint member; wherein a shaft portion extends axially outboard from at least a portion of said outer surface of said intermediate portion of said second joint member; wherein a plurality of axially extending shaft portion splines circumferentially extend along at least a portion of said outer surface of said shaft portion of said second joint member; wherein said plurality of axially extending shaft portion splines of said shaft portion of said second joint member has a first end portion, a second end portion and an intermediate portion interposed between said first and second end portions (468, 470) of said plurality of axially extending shaft portion splines; wherein at least a portion of said second end portion of said plurality of axially extending shaft portion splines has a shaft portion installation aid having a first end, a second end and a transition portion interposed between said first and second ends (488, 490) of said shaft portion installation aid; wherein said first end to said transition portion of said shaft portion installation aid defines a first portion of said shaft portion installation aid; wherein said transition portion to said second end of said shaft portion installation aid defines a second portion of said shaft portion installation aid; and wherein said outermost diameter of said plurality of axially extending shaft portion splines of said first portion and/or said second portion of said shaft portion installation aid is defined by a radius R2 from a centerline CL1 of said joint assembly, wherein, in a cross sectional plane perpendicular to the axis of said shaft portion, said intermediate portion of said plurality of axially extending shaft portion splines has a substantially polygonal shape, and characterised in that, in a cross sectional plane perpendicular to the axis of said shaft portion, said outer surface of said plurality of axially extending shaft portion splines of said shaft portion installation aid has a continuous arcuate or curved shape that is defined by a plurality of radii.