Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?

[Dui ni shuo de dui]

They're needle bearings rather than ball,

Yes, I haven't said anything about balls

That image shows it after I lost (?) 3(?) of the needlebearings somewhere, one from each of the "rollers".

Yeah that was kind of the point I was making. If you've already lost a few then the rest is likely to follow.

 

[amberwolf]

They weren't lost whiel operating. They were lost when I took it apart to clean the old grease out and to see what it looked like inside.

they can't come out unless you take it apart. (which could happen with any bearing disassembled that far).