Abstract: An inter-shaft bearing in a multiple body turbo-engine having an outer first shaft and an inner second shaft comprises bearing rollers disposed between an outer ring mounted on the first shaft and an inner ring mounted on the second shaft. The first shaft and the outer ring are provided with cooperating conical surfaces, and a plurality of fly-weights are disposed between the rear face of the outer ring and a retaining nut mounted on the first shaft. Each of the fly-weights has an inclined rear face which cooperates with a conical surface of the nut so that when centrifugal action during operation of the engine causes the fly-weights to move radially outwards they are simultaneously forced axially forwards to exert a thrust on the outer ring which thus tends to restrain the bearing through the action of the cooperating conical surfaces of the outer ring and the first shaft, thereby controlling bearing play.