A cartridge assembly for creating a pin joint between adjacent track shoes in a track chain, the pin joint extending through supporting bores (130, 132, 134) formed in the track shoes, the cartridge assembly comprising: a bushing having a first end face, a second end face, an outer surface, and an inner surface, the inner surface defining a bushing passage shaped as a cylindrical bore, wherein the bushing forms a lubrication reservoir adjacent the inner surface of the bushing and extending towards the outer surface of the bushing, the lubrication reservoir substantially aligned between the first end face and the second end face, and wherein the outer surface of the bushing corresponds with an outer diameter of the cartridge assembly; a track pin having a longitudinal axis, an outer surface, a first end, and a second end, the track pin disposed within the cylindrical bore of the bushing such that both the first end and the second end of the track pin extend past the bushing, wherein the bushing is rotatable with respect to the track pin, and wherein the outer surface of the track pin is in fluid communication with the lubrication reservoir; a first sleeve disposed about the track pin and adjacent to the first end face of the bushing; a second sleeve disposed about the track pin and adjacent to the second end face of the bushing; a first collar having an outer surface, a first end, and a second end, the first collar disposed about the track pin and the first end of the first collar disposed adjacent the first sleeve; and a second collar having an outer surface and a first end, the second collar disposed about the track pin and the first end of the second collar disposed adjacent the second sleeve; characterised in that, the outer diameter of the cartridge assembly is less than a diameter of supporting bores (130, 132, 134) such that the cartridge assembly, comprising the track pin, the bushing, the first sleeve, the second sleeve, the first collar and the second collar, is rotatable with respect to inside surfaces (164, 166, 168) of the supporting bores (130, 132, 134). a bushing having a first end face, a second end face, an outer surface, and an inner surface, the inner surface defining a bushing passage shaped as a cylindrical bore, wherein the bushing forms a lubrication reservoir adjacent the inner surface of the bushing and extending towards the outer surface of the bushing, the lubrication reservoir substantially aligned between the first end face and the second end face, and wherein the outer surface of the bushing corresponds with an outer diameter of the cartridge assembly; a track pin having a longitudinal axis, an outer surface, a first end, and a second end, the track pin disposed within the cylindrical bore of the bushing such that both the first end and the second end of the track pin extend past the bushing, wherein the bushing is rotatable with respect to the track pin, and wherein the outer surface of the track pin is in fluid communication with the lubrication reservoir; a first sleeve disposed about the track pin and adjacent to the first end face of the bushing; a second sleeve disposed about the track pin and adjacent to the second end face of the bushing; a first collar having an outer surface, a first end, and a second end, the first collar disposed about the track pin and the first end of the first collar disposed adjacent the first sleeve; and a second collar having an outer surface and a first end, the second collar disposed about the track pin and the first end of the second collar disposed adjacent the second sleeve; characterised in that, the outer diameter of the cartridge assembly is less than a diameter of supporting bores (130, 132, 134) such that the cartridge assembly, comprising the track pin, the bushing, the first sleeve, the second sleeve, the first collar and the second collar, is rotatable with respect to inside surfaces (164, 166, 168) of the supporting bores (130, 132, 134).