What must be done to any worn spacers, shafts, bearings, or housings?

When dealing with worn spacers, shafts, bearings, or housings, the most effective and reliable course of action is to replace these components. Over time and with use, mechanical parts can degrade due to factors such as wear and tear, stress, and environmental conditions.

Replacing worn components ensures that the machinery operates optimally and maintains reliability. It also helps in preventing further damage to interconnected parts which could lead to larger system failures, downtime, or costly repairs down the line. The integrity and performance of mechanical systems are heavily reliant on the condition of these components, thus making replacement crucial when wear is evident.

While refurbishment, repair, and adjustment may sometimes be options depending on the specific context and severity of the wear, they do not always restore the part to its original effectiveness, which can lead to riskier operational conditions. Therefore, replacement is the best practice for ensuring long-term functionality and safety in mechanical systems.