A work machine having a coupling arrangement for a towed implement, the coupling arrangement comprising a pair of rocker arms (16,18) and a pair of draft arms (20,22) having a pair of link assemblies interposed between and secured to the rocker arms and draft arms, each link assembly comprising: a sleeve having an internally threaded bore disposed therein and defining an axis A along its axial length; first and second rods (42, 44), the first and second rods (42, 44) having externally threaded end portions and distal connection ends, the externally threaded end portions of the first and second rods (42, 44) being positioned within the bore to threadingly engage the internally threaded sleeve to permit a length of the link assembly to be altered by rotating the sleeve relative to the first and second rods (42, 44); and a collar positioned over the sleeve and configured to slide relative the sleeve along axis A between an upper portion of the sleeve and a middle portion of the sleeve, and wherein the collar meshes with the upper portion so as to prevent rotational movement of the sleeve relative the collar when the collar is adjacent the upper portion, and wherein the sleeve is able to rotate relative the collar when the collar is adjacent the middle portion of the sleeve; and a locking handle mounted on the collar and pivotable between a locked position in which the handle is generally parallel with the axis A of the sleeve in which the collar is prevented from sliding along axis A relative the sleeve, and a released position generally perpendicular to the axis A in which the collar is able to slide relative the sleeve along axis A; and a locking mechanism, characterized in that the locking mechanism comprises: a locking plate mounted on the link assembly such that the locking plate is prevented from rotating relative an upper portion of the link assembly; and wherein in the locked position, the handle and collar engage the locking plate thereby preventing the collar from sliding along axis A relative the sleeve. a sleeve having an internally threaded bore disposed therein and defining an axis A along its axial length; first and second rods (42, 44), the first and second rods (42, 44) having externally threaded end portions and distal connection ends, the externally threaded end portions of the first and second rods (42, 44) being positioned within the bore to threadingly engage the internally threaded sleeve to permit a length of the link assembly to be altered by rotating the sleeve relative to the first and second rods (42, 44); and a collar positioned over the sleeve and configured to slide relative the sleeve along axis A between an upper portion of the sleeve and a middle portion of the sleeve, and wherein the collar meshes with the upper portion so as to prevent rotational movement of the sleeve relative the collar when the collar is adjacent the upper portion, and wherein the sleeve is able to rotate relative the collar when the collar is adjacent the middle portion of the sleeve; and a locking handle mounted on the collar and pivotable between a locked position in which the handle is generally parallel with the axis A of the sleeve in which the collar is prevented from sliding along axis A relative the sleeve, and a released position generally perpendicular to the axis A in which the collar is able to slide relative the sleeve along axis A; and a locking mechanism, characterized in that the locking mechanism comprises: a locking plate mounted on the link assembly such that the locking plate is prevented from rotating relative an upper portion of the link assembly; and wherein in the locked position, the handle and collar engage the locking plate thereby preventing the collar from sliding along axis A relative the sleeve.