A coupling for links of tracks, of the type comprising a pin which is integral with at least one first link , and a bushing , fitted rotatably over said pin , which is integral with at least one second link , wherein: - said pin comprises a cylindrical central portion which has a first predefined diameter and two end portions which have a second predefined diameter; - said pin comprises a non-through axial channel connected to the outside at one of its ends, and a substantially radial passage between the outer lateral surface of its central portion and said inner channel ; - said bushing comprises a through hole with a diameter which is larger than and proximate to the outside diameter of said central portion of said pin , on which it is arranged in the assembled configuration; - said pin supports respective sealing and alignment means which abut on respective end fronts of said bushing , for the confinement of the fluid lubricant interposed between said pin and said bushing ; said sealing and alignment means comprising at least one rigid spacer ring and an annular sealing gasket , characterized in that - the first predefined diameter is larger than the second predefined diameter; - said sealing and alignment means are supported by said pin substantially proximate to the end portions of said central portion ; and - said at least one rigid spacer ring is stably held on at least one end edge of said central portion of said pin , and - said annular sealing gasket externally surmounts said spacer ring and is provided with an elastically deformable lip which abuts on an end face of said bushing in order to isolate the interspace defined between said pin and said bushing , within which the fluid lubricant is confined. - said pin comprises a cylindrical central portion which has a first predefined diameter and two end portions which have a second predefined diameter; - said pin comprises a non-through axial channel connected to the outside at one of its ends, and a substantially radial passage between the outer lateral surface of its central portion and said inner channel ; - said bushing comprises a through hole with a diameter which is larger than and proximate to the outside diameter of said central portion of said pin , on which it is arranged in the assembled configuration; - said pin supports respective sealing and alignment means which abut on respective end fronts of said bushing , for the confinement of the fluid lubricant interposed between said pin and said bushing ; said sealing and alignment means comprising at least one rigid spacer ring and an annular sealing gasket , - the first predefined diameter is larger than the second predefined diameter; - said sealing and alignment means are supported by said pin substantially proximate to the end portions of said central portion ; and - said at least one rigid spacer ring is stably held on at least one end edge of said central portion of said pin , and - said annular sealing gasket externally surmounts said spacer ring and is provided with an elastically deformable lip which abuts on an end face of said bushing in order to isolate the interspace defined between said pin and said bushing , within which the fluid lubricant is confined. <EOS>