Most machine components contain rotating parts and, for this reason, rolling bearings are an integral part of mechanical equipment. Bearing subassemblies often have to carry considerable loads and rotate at high speeds. This all takes place with a small contact area between the bearing contact elements. Such difficult operating conditions result in frequent bearing failures. Failure of rolling bearings in machinery depends on many factors, such as overloading (especially when operating under variable loads and in high intensity machinery), inadequate lubrication, assembly errors, contamination, material fatigue. Loss of bearing life can perhaps be detected by monitoring dynamic parameters such as vibration or frictional moment. This article points out that the relationship between frictional moment and vibration level is not always obvious, and the use of bearings with contact seals requires additional analysis. The research presented here can contribute to a better understanding of the parameters frictional moment and vibration level. This can provide valuable insights into the development of low-friction bearings that are also dynamically stable (with low vibration levels), which is important in precision applications such as aviation or the medical industry.