Spider is nearing the end of its life. The main central hubs for the arms have been kept in good condition and it tells when you ride it. But I think the sea air is getting to it now.
Ranger mechanically is not that complicated. But its the fact it is old. It has suffered some issues during its time. I see this ride retiring at the park and it will be scrapped. I didn't sell in my eyes for a reason. It's due to all the modifications it had. Tumble bug won't see a life beyond the park either.
Dodgems havent had a change at all. Even the transformer that runs them is the same from the late 80's I think. Most of these rides have been in the park since the mid-'90s. So in a way, if they go its a good thing. They served their purpose.