Abstract: A steering system includes a steering operation shaft, a lower shaft, an upper shaft, and an intermediate shaft. The intermediate shaft includes a tubular member including a hollow portion; and a shaft member. An oil groove that retains lubricating oil is provided in a predetermined range in an axial direction of the intermediate shaft on at least one of an outer peripheral surface of the shaft member at a part housed in the hollow portion and an inner peripheral surface of the hollow portion of the tubular member. A sectional area of the oil groove in an upper shaft-side part of the predetermined range is larger than a sectional area of the oil groove in a lower shaft-side part of the predetermined range, the upper shaft-side part being located on a side of the upper shaft, and the lower shaft-side part being located on a side of the lower shaft.

Abstract: A steering system includes a steering operation shaft, a lower shaft, an upper shaft, and an intermediate. The intermediate shaft includes a tubular member including a hollow portion; and a shaft member. An oil groove that retains lubricating oil is provided in a predetermined range in an axial direction of the intermediate shaft on at least one of an outer peripheral surface of the shaft member at a part housed in the hollow portion and an inner peripheral surface of the hollow portion of the tubular member. A sectional area of the oil groove in an upper shaft-side part of the predetermined range is larger than a sectional area of the oil groove in a lower shaft-side part of the predetermined range, the upper shaft-side part being located on a side of the upper shaft, and the lower shaft-side part being located on a side of the lower shaft.