Abstract: A friction disc. The friction disc includes a plate having a forward facing plate surface, a rearward facing plate surface, an inward facing plate surface, and an outward facing plate surface. An inward facing plate surface has a plate lug extending radially inwardly. The friction disc includes a hub having an inward facing hub surface and an outward facing hub surface. The outward facing hub surface has a hub lug extending radially outwardly. The friction disc includes a damping web connecting the plate to the hub to transmit torque between the plate and the hub to rotate the plate and the hub mutually. The damping web includes a resiliently deformable material that limits transmission of shock between the plate and the hub.

Abstract: A clutch assembly. The assembly includes a cover having a threaded inwardly facing surface and an adjusting ring having a threaded outwardly facing surface threadably received in the inwardly facing surface of the cover. The assembly also includes a pressure plate, a friction disc, a lever reacting against the adjusting ring to move the pressure plate into and out of engagement with the friction disc, and an adjustment mechanism. The assembly includes an elastically compressible seal assembly extending between opposing axially facing surfaces of the cover and the adjusting ring to prevent contamination from passing the seal assembly and accumulating on the threaded inwardly facing surface of the cover.

Abstract: A friction disc. The friction disc includes a plate having a forward facing plate surface, a rearward facing plate surface, an inward facing plate surface, and an outward facing plate surface. An inward facing plate surface has a plate lug extending radially inwardly. The friction disc includes a hub having an inward facing hub surface and an outward facing hub surface. The outward facing hub surface has a hub lug extending radially outwardly. The friction disc includes a damping web connecting the plate to the hub to transmit torque between the plate and the hub to rotate the plate and the hub mutually. The damping web includes a resiliently deformable material that limits transmission of shock between the plate and the hub.

Abstract: A clutch assembly. The assembly includes a cover having a threaded inwardly facing surface and an adjusting ring having a threaded outwardly facing surface threadably received in the inwardly facing surface of the cover. The assembly also includes a pressure plate, a friction disc, a lever reacting against the adjusting ring to move the pressure plate into and out of engagement with the friction disc, and an adjustment mechanism. The assembly includes an elastically compressible seal assembly extending between opposing axially facing surfaces of the cover and the adjusting ring to prevent contamination from passing the seal assembly and accumulating on the threaded inwardly facing surface of the cover.

Abstract: A method of converting from a first clutch of the type comprising a relatively wide-profile cover having an integral circular rim attached to one face of a flat rimless flywheel, to a second clutch of the type comprising a relatively thin-profile cover. The method comprises detaching the first clutch with the wide-profile cover from the flywheel, applying the second clutch including the thin-profile cover and an adaptor ring to one face of the flywheel with the adaptor ring disposed between the cover and the flywheel, and removably attaching the cover and adaptor ring to the flywheel.