An actuation system for deploying and retracting a lift assisting device of a wing of an aircraft, is presented. The actuation system includes a track pivotally coupled to the lift assisting device, a shaft rotating in response to flight control signals to deploy or retract the lift assisting device, means for actuating the lift assisting device between a retracted position and a deployed position along an arcuate path, a plurality of track roller bearings and a plurality of side roller bearings. The roller bearings rotatably contact the track to guide the track along the arcuate path. The track roller bearings are comprised of an outer ring, a split inner ring and liners disposed between bearing surfaces of the outer and the inner rings. The split inner ring is configured for accommodating deflection and bending of a mounting pin coupling the track roller bearing in proximity to the track.