In order to determine whether removing bearings can be used to check after the bearings clean, carefully check the roller surface, scroll, status of the mating surfaces, wear of the cage, the increase in bearing clearance and there's no falling damage, abnormal size precision. Non-separation of small ball bearings, supporting inner rings with one hand horizontally, rotate the outer ring to confirm in a smooth rotation State. Tapered roller bearings are separable bearings, rolling element and the Raceway in the outer ring can be respectively checked. Larger bearings cannot rotate, check rolling element and the Raceway, cage, sidewall surface appearance. the importance of as high as possible shall be carefully inspected.