If the printer is working and not grinding or making noises that indicate parts are wearing down I would leave it alone.
As for lubrication I've been told that if needed, you should use the correct lubrication materials designed for inkjet printers. Do NOT use mineral oil or WD40.
Couldn't find my original reference from.. erm... 10 years ago! but the short version is that Epson has specific compounds that they manufacture for different jobs.
Having looked a bit further the general rule of thumb is that you can very lightly oil cogs, etc.. but better to use a silicon grease for the printhead rail.
I'll query a tech service we've known for a while, for their input and report back as/when.
Yeah, I know... only a "bit"... Unfortunately I'm aware that there are a few things I've stored away over time that I can't relocate the source for to reaffirm what I learned of old. I'm not alone in that I'm sure but when you're giving advice it pays to be right rather than just confident.
When troubleshooting printer issues you do not always have the luxury of being immediately right. But you can have confidence that the process taken will eventually lead to a supported conclusion.
