I followed the directions on cleaning the e-box fan from Ken Yee's site, and the noise has gone away for now. I noticed though, that on step 8, he says "I also lubricated the bearings (per Wolfgang)". I don't see anything on Wolfgang's site that mentions lubricating the bearings. Can anyone tell me how to do that? I couldn't even get the electric motor out of the plastic enclosure (it seemed like it would be difficult to do without damaging the plastic fan, so I didn't push my luck), but even if I was able to do that, I don't know how to lubricate the bearings.

I'll probably replace it with the newer model fan eventually, but I have to get the auxiliary fan fixed first, so I'm hoping the existing e-box fan can limp along for a little while.