Final answer:
Bearings are not side-specific and can be installed on either side of a hub if they are identical and the hub is designed symmetrically. However, it is generally recommended to use new bearings and ensure correct installation techniques for optimal performance.
Step-by-step explanation:
The question is about whether bearings need to be installed into the same side of the hub from which they were removed. In general, when reinstalling bearings, it's important to ensure that they are placed into a hub that is clean and free from damage. However, the bearing itself is not 'side-specific'—meaning a bearing that was removed from one side can theoretically be installed on the other side, provided that the bearings are identical and the hub is designed symmetrically. Nonetheless, best practice suggests using new bearings to maintain optimal performance and reliability of the machinery. It is crucial in most cases that bearings are installed correctly with the proper orientation and alignment, using the correct tools and methodology. Failure to do so can lead to premature failure of the bearing and potential damage to the machine.