Abstract: A loose joint assembly for linking two segments of a shaft which are substantially aligned at either end of the joint assembly co-axially about a axis of rotation. The joint assembly includes a male coupling member disposed co-axially within a female coupling member with an intermediate bearing member to align the coupling members. The male coupling member has a plurality of circumferentially spaced flats located within the space enclosed by the female coupling member. A corresponding plurality of openings, preferably in the form of slots extending in the circumferential direction, are located in the female coupling member, each slot being aligned with a corresponding flat. A drive pin is attached to the male coupling member at each flat and extends radially from the flat and at least partially into the corresponding slot in the female coupling member.