Small fans / maintenance / oiling / noise

[vjekobalas]

Although there is quite a bit of info on web about this, wanted to see what the consensus
here is about oiling of small fans for maintenance or if they are noisy and does type of oil
matter for ball bearing / sleeve bearing and whether oiling should be done when mounted above
electronic components.On the web, a variety of oils are suggested from sowing machine oil to engine oil.

I understand the difference between ball bearing and sleeve bearing but haven't
removed stickers or pulled fans apart so not sure how to identify if it's relevant.

As an example. attached are photos of two fans in a machine - they are the same, just sticker
removed I presume.

[wraper]

If there is something wrong with a fan and If it has ball bearing, forget about it, bearing is dead. Buy a new fan, likely will be cheaper than replacement bearings. If the sleeve bearing is wobbly, forget about it too. Only if sleeve bearing that is still tight replacing the lube is somewhat worth it. If there is nothing wrong with a fan, just leave it alone.

[Haenk]

In general, small bearings can not be serviced, they just wear out over time and need to be replaced.
Oil or fat does not help, at least not for long.

[tunk]

Never done it for maintenance, but I have done it a
handful of times with success on dead/non-rotating
fans. I think they had ball bearings and it may be that
the original oil had gummed up.

[wraper]

Never done it for maintenance, but I have done it a
handful of times with success on dead/non-rotating
fans. I think they had ball bearings and it may be that
the original oil had gummed up.

95% chance they had sleeve bearings. Those small ball bearings really fail, there is nothing to repair by lubrication. Not to say simply putting the oil inside is a half-assed job. You need at least take it apart and clean the old lubrication which turns into sticky junk.

[Alex_Baker]

I know that sleeve bearings can sometimes accumulate dust (in a PC for example) and seize up, at that point I figure it would be possible to disassemble and clean/reoil everything.

I personally have had limited success oiling fans with sleeve bearings, it all depends on weather it is already worn out, which most of the time it is. Not to mention that some fans can be a pain to take apart and you risk damaging them.

[BrokenYugo]

I've often shut up a loud one for a while with oil, but it never seems to last very long. It is a "keep it limping along" sort of repair.

As preventive maintenance, maybe oil the sleeve type, ball bearing is more questionable since you're just as likely to wash out good grease as you are to rejuvenate dried out grease. Oil sparingly in any event.

[vjekobalas]

Thanks to all for the input - seems like replacement is the only sure maintenance.

[BradC]

Thanks to all for the input - seems like replacement is the only sure maintenance.

It is. Sometimes however a replacement can't be obtained in a timely manner and you need a band-aid to get you through.

In sleeve bearing fans I find any xw50 motor oil helps significantly. Nice and thick to fill up some of the wear slop. With ball bearings I wash them out in shellite (which is just a very light clean hydrocarbon). Petrol would do as well. Then I soak them in iso46 synthetic compressor oil (because it's what I have handy). Let them sit for a while for the excess to drain out and then put them back.

Then I go and order a replacement fan. In 2 instances with ball bearings the replacement fans have been sitting on the shelf for about 5 years waiting for the re-lubed ones to die. Haven't yet. Sleeve bearing fans with the thicker oil often last many months past the arrival of the replacement fans.

Heck, I re-lubed the seized ball bearings in my toilet exhaust fan back in 2010 and I'm still waiting for them to die.

It's probably having the replacements on hand that makes them last so long. If I couldn't get a replacement or didn't bother I'm sure the re-lubed bearings would lock up in short order, simply because Murphy is a bastard.

[inse]

I will try your tactics on my charger.
The fan failed after two years with noise and sometimes not even spinning up, the replacement started doing the same after months, or was it only weeks?
So I will order replacement and relubricate in parallel (-: