Bill,
All of the advise given thus far is very good but I can tell from your postings that you still unsure of what you have and how its supposed to work.
My humble advice would be to find someone locally knowable in O gauge trains to help you sort out which engines may need repair and which ones simply need a good cleaning and lubrication. Should you have a good local train store that sells O gauge trains and has a layout, take a few of your engines to them for assistance. I'm certain they'd be happy to assist you and they will be able to answer all of your concerns.
Inheriting modern O gauge trains can be dauting at first, as there are many variants due to evolution of a brands product. This is why I'm suggesting you seek advice from local experts who you can establish a working relationship with to help clear-up the confusion you are experiencing.
