Abstract: A planet gear type hub gear for transmitting torque between a drive shaft and a vehicle wheel. The end portion of the drive shaft carries a sunwheel which cooperates with a plurality of planet wheels mounted on a planet wheel holder secured to the vehicle wheel. The planet wheels are meshing with a gear ring that is mounted on a fixed gear ring retainer, and that is locked axially on said retainer by means of at least one locking means. Said locking means engages grooves on both the gear ring and the gear ring retainer. In the planet wheel holder there is at least one passage via which the locking means can be operated by means of an elongate tool so as to make the gear ring, together with sunwheel planet wheels and planet wheel holder, axially removable from the gear ring retainer in a single unit enclosed by the hub casing.