Suspension system comprising a body provided with a cylindrical cavity in which is slidably mounted, along a longitudinal axis Z, a piston dividing the cylindrical cavity into two working chambers: a lower chamber and an upper chamber each receiving a gas, the piston being connected to a piston rod emerging from the cylindrical cavity through a sealing ring, the suspension system comprising means to arrange an angular clearance of predetermined magnitude of the axis of the piston rod relative to the axis of the cylindrical cavity, said means comprising: - at the piston a thick ring bearing on the inner face of the cylindrical cavity and comprising a through-bore in which takes place an end part fastened to the end of the rod of the piston, a lateral clearance of predetermined amplitude being arranged between the inner diameter of the thick ring and the outer diameter of the end part, the suspension system being characterised in that said means comprise: - an O-ring being jointly pinched between the transversal faces of the end part and of the thick ring, - at the sealing ring, an external ring comprising a substantially tubular portion secured to a portion forming an internal washer perpendicular to the longitudinal axis Z, in the central portion thereof, the tubular portion being fixed inside the end of the cylindrical body, the portion forming an internal washer being pinched between a cup secured to the piston rod, and a nut that is screwed onto a partially threaded tubular extension of said cup, the outer diameters of the cup and of the tubular extension thereof, being less than a predetermined clearance at the inner diameters of the substantially tubular part and of the portion forming an internal washer respectively, an O-ring being inserted between a transversal face of the cup and the corresponding face of the portion forming an internal washer of the external ring. - at the piston a thick ring bearing on the inner face of the cylindrical cavity and comprising a through-bore in which takes place an end part fastened to the end of the rod of the piston, a lateral clearance of predetermined amplitude being arranged between the inner diameter of the thick ring and the outer diameter of the end part, the suspension system being characterised in that said means comprise: - an O-ring being jointly pinched between the transversal faces of the end part and of the thick ring, - at the sealing ring, an external ring comprising a substantially tubular portion secured to a portion forming an internal washer perpendicular to the longitudinal axis Z, in the central portion thereof, the tubular portion being fixed inside the end of the cylindrical body, the portion forming an internal washer being pinched between a cup secured to the piston rod, and a nut that is screwed onto a partially threaded tubular extension of said cup, the outer diameters of the cup and of the tubular extension thereof, being less than a predetermined clearance at the inner diameters of the substantially tubular part and of the portion forming an internal washer respectively, an O-ring being inserted between a transversal face of the cup and the corresponding face of the portion forming an internal washer of the external ring. - an O-ring being jointly pinched between the transversal faces of the end part and of the thick ring, - at the sealing ring, an external ring comprising a substantially tubular portion secured to a portion forming an internal washer perpendicular to the longitudinal axis Z, in the central portion thereof, the tubular portion being fixed inside the end of the cylindrical body, the portion forming an internal washer being pinched between a cup secured to the piston rod, and a nut that is screwed onto a partially threaded tubular extension of said cup, the outer diameters of the cup and of the tubular extension thereof, being less than a predetermined clearance at the inner diameters of the substantially tubular part and of the portion forming an internal washer respectively, an O-ring being inserted between a transversal face of the cup and the corresponding face of the portion forming an internal washer of the external ring.