The invention relates to a jack (4) for moving a movable panel of a vehicle, including: a endless screw and nut assembly (14) defining an axis (22); a bearing (20) in which an element (14) selected from the nut and the screw, for example the latter, is rotatably mounted; and a tensioner (60) which is force-fitted onto the element or onto the bearing and which biases the latter by means of mutual axial bearing when the jack is inoperative.