Abstract: A torsion damper comprises a main damper plate surrounding a hub, and a pre-damper mounted on one side of the main damper plate and having a housing which is coupled to the main damper plate for rotation with the latter, by coupling fingers each of which is engaged in a complementary aperture formed in the main damper plate. Guide rings of the pre-damper are retained axially between a first shoulder formed on a set of resiliently deformable hooked tongues, and a second shoulder, with both these shoulders being carried by the housing.Each hooked tongue extends radially inside a corresponding coupling finger and is also arranged to penetrate into the aperture corresponding to the associated coupling finger.

Abstract: The circumferentially acting elastic cushion disposed between two coaxial parts of a torsional damper comprises at least one elastically deformable arm. This is attached at one end to the annular flange of one of the coaxial parts. Its other end is unsupported and has a shoulder adapted to engage another shoulder provided for this purpose on the other of the two coaxial parts.