A method for assembling a composite housing fitted with a shaft and associated mounted elements comprising the steps of: a) arranging the housing in a predetermined position with respect to an actuator , the housing having at least one opening adapted to receive a shaft ; b) arranging the shaft in a predetermined position with respect to the housing and the actuator ; c) selecting an element to be mounted on the shaft within the housing , the element having an opening adapted to receive the shaft ; d) conveying the element into a predetermined position within the housing ; e) pushing the shaft by means of the actuator so that it passes successively through the opening in the housing and that in the element to be mounted; wherein the method comprises the additional steps of: f) subsequent to selecting the element to be mounted on the shaft within the housing according to step c), and prior to conveying the element into a predetermined position within the housing according to step d): locating it in a position adjacent a heat source for a predetermined time; g) subsequent to step e): selecting at least one additional element and conveying it into a predetermined position within the housing , said additional element having an opening adapted to receive the shaft , and, subsequent to selecting the additional element to be mounted on the shaft within the housing , and prior to conveying the additional element into a predetermined position within the housing locating it in a position adjacent a heat source for a predetermined time; and h) pushing the shaft by means of the actuator so that it passes through the opening in the additional element to be mounted. a) arranging the housing in a predetermined position with respect to an actuator , the housing having at least one opening adapted to receive a shaft ; b) arranging the shaft in a predetermined position with respect to the housing and the actuator ; c) selecting an element to be mounted on the shaft within the housing , the element having an opening adapted to receive the shaft ; d) conveying the element into a predetermined position within the housing ; e) pushing the shaft by means of the actuator so that it passes successively through the opening in the housing and that in the element to be mounted; wherein the method comprises the additional steps of: f) subsequent to selecting the element to be mounted on the shaft within the housing according to step c), and prior to conveying the element into a predetermined position within the housing according to step d): locating it in a position adjacent a heat source for a predetermined time; g) subsequent to step e): selecting at least one additional element and conveying it into a predetermined position within the housing , said additional element having an opening adapted to receive the shaft , and, subsequent to selecting the additional element to be mounted on the shaft within the housing , and prior to conveying the additional element into a predetermined position within the housing locating it in a position adjacent a heat source for a predetermined time; and h) pushing the shaft by means of the actuator so that it passes through the opening in the additional element to be mounted. <EOS>