Abstract: A motor vehicle door lock or the like comprises a locking mechanism for securing and releasing the door, operated by a lock which is disengageable from the locking mechanism. The disengageable lock comprises a stator, a tubular intermediate sleeve, a rotor operable by a key, and a control lever for actuating the locking mechanism. The control lever is coupled to the rotor through a driving sleeve. The lock also includes an indexer which is moveable axially between a rest, or engaged, position and a disengaged position when the intermediate sleeve is rotated during actuation of the rotor by an incorrect key. This axial movement of the indexer displaces the driving member axially to a position in which the driving member is prevented from rotating. The indexer is fixed in rotation to the intermediate sleeve, and is also free to rotate with respect to the stator when in the disengaged position.