An axlebox retainer key (50) is disclosed for fitting to a pedestal leg (24) of a sideframe of a rail wagon bogie. The key (50) comprises a body which has a basal projection (52) which extends in use into a cavity or hole (42) which is formed in the pedestal leg (24). The key (50) also has an upper surface recess (60) which is arranged to receive a locking pin (66) which can be axially inserted to maintain the key (50) at the pedestal leg (24). The locking pin (66) is also inserted via the pedestal leg side wall (30) which incorporates a through-hole (82) through which the locking pin (66) is passed. To install the key (50), an operator first positions the basal projection (52) of the key (50) in the cavity or a hole (42) that is formed in the pedestal leg (24), and then moves the locking pin 66 across the key (50) via the through-hole (82) in the side wall (30) so as to secure the key (50) to the pedestal (24).