Abstract: This invention relates to a clutch mechanism, having a cover which includes an annular lateral wall and a pressure plate adapted to engage at least one transverse bearing shoulder formed integrally with the cover. The bearing shoulder is intended to axially retain the pressure plate relative to the cover against the action of the clutch spring, e.g. during storage. The retaining shoulder is formed directly on the cover, for example on the peripheral radial rim thereof, by means of a recess formed in the lateral wall. This enables a bayonet-type mounting of the pressure plate within the cover.