A floating spacer assembly for a gear mounted on a shaft, such as a planet gear mounted to a planet carrier, is disclosed. The gear may be mounted on the shaft with a pair of roller bearings with inner races and bearing rollers, and a gear bore having a gear groove defined therein functioning as the outer races of the roller bearings. The floating spacer assembly may include an annular spacer ring having one or more sector slots circumferentially spaced around the spacer ring, and a spacer sector disposed within each of the sector slots and extending radially outward from the spacer ring and into the gear groove when the floating spacer assembly is installed between the roller bearings. The spacer sectors may engage surfaces of the gear groove and the spacer ring may engage the bearing rollers to limit axial movement of the gear relative to the shaft.