Patent ID: 7305765

Claim:
A method of processing a wheel bearing unit that includes a stationary ring that has a stationary raceway on a stationary peripheral surface and is not rotated in operation, a rotary ring that has a rotary raceway on a rotary peripheral surface and is rotated in operation, a plurality of rolling elements provided between the stationary raceway and the rotary raceway, an encoder fixed to a part of the rotary ring and at least a part of the encoder is made of a permanent magnet, a cover fixed on an opening portion of an axially inner end of the stationary ring and having an insertion hole for inserting a part of a holder of a sensor in operation, and a rotary flange provided to an outer peripheral surface of the rotary ring, wherein said rotary flange couples/supports a braking rotating body on a side surface of the rotary flange at least in operation, the braking rotating body having a braking friction surface against which a friction material is pushed in a braking operation, comprising: processing a portion of the wheel bearing unit or the braking rotating body into predetermined shape and dimension in a state that the stationary ring, the rotary ring, and the plurality of rolling elements are assembled together, wherein prior to the processing a space in which the encoder is provided is isolated from an outside by fitting a stop plug to the insertion hole of the cover, and removing the stop plug from the cover after the portion of the wheel bearing unit is processed into predetermined shape and dimension but before the wheel bearing unit is fitted to a suspension system.