A planet gearbox for connection to a carrier (90, 92) of an epicyclic gearing arrangement in a gas turbine engine that includes a sun gear and a ring gear surrounding the planet gearbox and the sun gear, the planet gearbox comprising: an inner ring defining a generally cylindrical shape having a virtual central axis of rotation, the inner ring defining a forward end and an aft end disposed axially spaced apart from the forward end, the virtual central axis of rotation having a midpoint disposed halfway along the length of the inner ring, the inner ring having an interior surface that defines a hollow interior cavity having a forward opening and an aft opening disposed axially spaced apart from the forward opening, the inner ring's forward opening being defined by a forward annular surface facing inwardly toward the virtual central axis of rotation and having a larger diameter section and a smaller diameter section, the smaller diameter section being disposed closer to the midpoint of the virtual central axis of rotation than the larger diameter section, the inner ring's aft opening being defined by an aft inner annular surface facing inwardly toward the virtual central axis of rotation and having a larger diameter section and a smaller diameter section, the smaller diameter section being disposed closer to the midpoint of the virtual central axis of rotation then the larger diameter section, the inner ring defining an outer surface facing outwardly away from the virtual central axis of rotation, the inner ring's outer surface defining at least one track, each track being configured to receive and rotatably guide therein a respective plurality of rotatable members, each rotatable member being freely rotatable with respect to the outer surface of the respective track of the inner ring; a forward support plug configured to be fixed to the carrier and the forward opening of the inner ring, the forward support plug defining a generally cylindrical shape about the virtual central axis, the forward support plug having a forward end and an aft end disposed axially apart from the forward end, the aft end of the forward support plug defining an outer surface that is radially equidistant from the virtual central axis and configured to be received within the forward opening of the inner ring, the forward end of the forward support plug defining an outer surface that is radially equidistant from the virtual central axis and has a larger diameter than the outer surface of the aft end of the forward support plug; and an aft support plug configured to be fixed to the carrier and the aft opening of the inner ring, the aft support plug defining a generally cylindrical shape about the virtual central axis, the aft support plug having a forward end and an aft end disposed axially apart from the forward end, the forward end of the aft support plug defining an outer surface that is radially equidistant from the virtual central axis and configured to be received within the aft opening of the inner ring, the aft end of the aft support plug defining an outer surface that is radially equidistant from the virtual central axis and has a larger diameter than the outer surface of the forward end of the aft support plug; wherein the outer surface of the forward end of the forward support plug is fixed by a press fit to the larger diameter section of the forward annular surface of the forward opening of the inner ring; and wherein the outer surface of the aft end of the aft support plug is fixed by a press fit to the larger diameter section of the aft annular surface of the aft opening of the inner ring. an inner ring defining a generally cylindrical shape having a virtual central axis of rotation, the inner ring defining a forward end and an aft end disposed axially spaced apart from the forward end, the virtual central axis of rotation having a midpoint disposed halfway along the length of the inner ring, the inner ring having an interior surface that defines a hollow interior cavity having a forward opening and an aft opening disposed axially spaced apart from the forward opening, the inner ring's forward opening being defined by a forward annular surface facing inwardly toward the virtual central axis of rotation and having a larger diameter section and a smaller diameter section, the smaller diameter section being disposed closer to the midpoint of the virtual central axis of rotation than the larger diameter section, the inner ring's aft opening being defined by an aft inner annular surface facing inwardly toward the virtual central axis of rotation and having a larger diameter section and a smaller diameter section, the smaller diameter section being disposed closer to the midpoint of the virtual central axis of rotation then the larger diameter section, the inner ring defining an outer surface facing outwardly away from the virtual central axis of rotation, the inner ring's outer surface defining at least one track, each track being configured to receive and rotatably guide therein a respective plurality of rotatable members, each rotatable member being freely rotatable with respect to the outer surface of the respective track of the inner ring;