Actions to be taken 3.1.1 Marking of split parts When there are several bearings of the same type in the same bearing arrangement, all bearings are numbered and their positions are recorded. The side of the bearing used in the configuration shall be marked including marking the mounting position of the bearing. Mark the radial installation direction of the ferrule according to the external force. 3.1.2 Finished bearing test Noise detection Detection of axial/radial clearance Detection of radial/axial runout Detection of friction torque 3.1.3 Bearing disassembly If the sealed bearing leaks grease, determine the amount of grease. Carefully remove the dust cover or seal from the sealed bearing, avoiding deformation as much as possible. Evaluate grease distribution in bearings. Grease sampling; take multiple samples if there are irregular lubrication patterns. If disassembly is destructive, it is possible to damage areas that do not affect the cause of the failure (such as cutting or turning off the rib on the small diameter end of the tapered roller bearing). If damage is unavoidable during disassembly, mark it and record it. Evaluating bearing components begins with a careful look at the main running and mounting surfaces. Microscopic inspection of bearing components is recommended and is usually required for most bearings. The following procedures are often applicable for evaluating bearing components: Evaluation: Mating surfaces (axial mating surfaces, inner ring bore, outer ring outer surface) Raceway rib seal mating surfaces/contact surfaces Rolling element (outer surface and end faces of rollers) Cage seals sometimes require additional testing in order to identify the cause of failure. These inspection items include: lubricant analysis, measurement, electron microscope test, etc. In the laboratory of FAG Bearings, relevant staff are willing to provide assistance in product development (refer to Chapter 4). A choice is often made: keep the bearing in service or replace it immediately? When failure is evident, these procedures are unquestionably followed. However, such failures are rare. An evaluation of a bearing usually reflects its service conditions. When abnormal conditions and causes are detected, further damage can often be avoided. The following sections include a description of the phenomenon, its causes, and appropriate, preventative measures that can be taken.