A coupling assembly (10) for connecting an implement propeller shaft of a PTO drive of a tractor, the coupling assembly (10) comprises a PTO adapter shaft (20) and a PTO stub shaft (14). The PTO adapter shaft (20) has a first bore (25) which forms internal splines (34) and has a second blind bore (26) which extends from the first bore (25) to an end wall (28) which faces towards the first bore (25). The first bore (25) has a larger diameter and the second blind bore (26) has a smaller diameter. The PTO stub shaft (14) has a larger diameter shaft portion (60) with external splines (61) for meshing engagement with the internal splines (34) of the PTO adapter shaft (20) and has a smaller diameter shaft portion (58) which extends away from the larger diameter shaft portion (60). The smaller diameter shaft portion (58) has an outer end with a chamfer (64) and first and second journals (66, 68) formed thereon. The first journal (66) is spaced axially apart from the second journal (68). The first and second journals (66, 68) are slidably received by the second blind bore (26).
