A lifting tool (2) for use in lifting components (1,5) from a wind turbine gearbox during service or repair comprises a frame-like structure comprising interconnected beams (4,6,8,8,10,12,20,22,24,26,28) for securing to the gearbox housing once an upper housing part has been removed to provide an opening to the gearbox interior, the tool being secured to the gearbox at a periphery of the opening, and further comprising one or more pulleys (36) mounted on the frame-like structure, a lifting chain, cable, wire or rope extending over the pulley or pulleys attachable to a component (1) within the gearbox, the frame-like structure comprising a number of inter-connectable modules.