A locking mechanism (10) for an implement link of an agricultural vehicle includes a support strut (11) connectable at one end to the implement link, a housing (13), a pivoting arm (15), a locking body (19) and a tensioning device (20, 21, 22). The arm (15) is connected at a first end to the support strut (11) remote from the implement link and has a recess (18) in a second end. The locking body (19) is slidably mounted to the housing (13) and is movable between a locked position within the arm recess (18) and an unlocked position clear of the recess. The tensioning device (20, 21, 22) is a sprung linkage arrangement coupled with the locking body and movable between a first position in which the locking body is held in the unlocked position and a second position in which the locking body can move to the locked position when the locking body (19) and arm recess (18) are aligned.
