Do you even do maintenance that you’re not quite sure why it’s required? Could be you’re not doing maintenance “by-the-book,” but by word-of-mouth.
Word-of-mouth maintenance is not always bad. A lot of good info gets passed that way. But so does a lot of out-of-date info. And a lot of wrong info, too!
Don’t do maintenance that is not covered in your TM unless the maintenance objective is clear the special circumstances for doing it are well-defined.
Question all maintenance that seems to be word-of-mouth. Technology is constantly changing equipment, like gas engines to diesel or batteries requiring maintenance to batteries that are maintenance-free, but some of us stubbornly hold on to out dated maintenance techniques.
Understanding why a preventive maintenance task is required is an important motivator for doing that maintenance. If your TM does not tell you to do a specific preventive maintenance task and your objective is not clear, it could be that word-of-mouth has you doing work no longer needed.