FAG bearings should it be repair specific judgments, that bearings are already full and the near destruction of the specific judgment as follows:
　　1) using the bearing working status monitoring instrument
　　Such as ferrograph or I-ID-1 or SPM bearing monitoring equipment to determine bearings FAG bearings when it should take to repair work and decisions, this is the most convenient and reliable way.
　　For example, when using the HD-1 instrument, and when the pointer by the warning zone close to the danger zone, and in taking measures, such as improved lubrication a pointer does not return, will be able to judge the problem with the bearing itself, when not in the danger area at this time, bearing repair. How far away from the danger area begin to repair, can be adjusted by experience.
　　Using this instrument, you can take full advantage of potential bearing, FAG bearings to be repaired in a timely manner, and avoids the failure occurred, is safe and economical.
　　2) using a simple tool monitoring
　　In the absence of the above devices, the operator can be armed with rods or tools such as wrenches machine shell parts of the subject closest to the bearing, ear ashamed tool by tool FAG bearing play sound coming from monitor on, of course, used medical stethoscope modified can also.
　　Normal of bearing running sound should is uniform, smooth not harsh of sound, and not normal of bearing running sound is has variety of intermittent, impact sexual or harsh of sound. first to habits Yu normal of bearing running sound, then on can grasp judgment not normal of bearing running sound, then through practice experience of accumulated, and further can analysis out what of not normal sound corresponds to Yu what of FAG bearing not normal phenomenon. Categories of abnormal sound of bearings much difficult to think, primarily based on the experience accumulated.