PRELOAD INSPECTION METHOD FOR BEARING DEVICE FOR VEHICLE WHEEL

The preload inspection method for wheel bearing devices comprises: a press-fitting step (S02) for press-fitting an inner ring (4) into a small diameter step part (3a); a first bearing preload value calculation step (S03) for calculating a first bearing preload value (P1) on the basis of an axial negative gap (G1) between a raceway surface and a rolling element after the press-fitting step (S02); a post-press-fit rotational torque measurement step (S05) for measuring a post-press-fit rotational torque (Ta) after the press-fitting step; a crimping step (S06) for crimping the small diameter step part to the inner ring after the post-press-fit rotational torque measurement step; a post-crimping rotational torque measurement step (S07) for measuring a post-crimping rotational torque (Tb) after the crimping step; a second bearing preload value calculation step (S08) for calculating a second bearing preload value (P2) by adding a preload change amount (ΔP) based on a difference torque (ΔT) between the post-press-fit rotational torque (Ta) and the post-crimping rotational torque (Tb) to the first bearing preload value (P1); and a determination step (S09) for determining the suitability of the preload depending on whether or not the second bearing preload value (P2) is within a range of a reference value.