Sleeve bearings fans have a well-deserved reputation of wearing out quickly. But they’re inexpensive, and not necessarily cheaply made. They can perform very well indeed. We want to use them on our heatsinks, but we worry that they will fail and leave our CPU’s overheating. Wouldn’t you like to be able to use a sleeve bearing fan and not have to worry? Read on.
If you peel back the label and pop the cap of sleeve bearing fans you will find many have lubrication wells that are dry as the proverbial bone. In other words, no matter how well-designed the fan, if it is assembled without enough oil, its life will be shortened. And it might not perform as well as it should. In one case I sped up a fan by 15%, just by putting a couple drops of oil in it. That turned out to be a crucial increase, because the fan went from essentially useless to pushing a fair amount of air. And that fan will last a lot longer with oil in its well than if it had run with a dry bearing.
I would recommend lubricating every fan that has a well you can get to — that includes any ball bearing fan — before putting it in service. For sleeve bearing fans you should inspect their lubricant wells every six months or so, and top up those that need it. It’s a lot like changing the oil in your car. Preventative maintenance.
So, how do you lubricate a fan?
1. Gather your materials. Any machine oil will do. If you are oiling a ball bearing fan, a light oil would penetrate through tight clearances, but in a sleeve bearing fan you may want a heavier oil that will tend to cling to surfaces. Probably the best compromise is Singer sewing machine oil, available at Wal-Mart and other places for under $3.00. I have used a number of oils. No problems with any so far. You might even want to dip a little from a can of car oil. According to some who have tried it, it does work.
2. Peel back the label. Most sleeve bearing fans have a little cap that holds in the oil. Ball bearing fans tend not to have a cap. They seem to believe their bearings are sealed. Maybe so, but you can watch a low viscosity oil seep in. That’s not really sealed, is it? But there are fans with hard plastic well covers that are glued tight. Let those be.
3. Pop the cap. I use a toothpick because it is wood, and less likely to damage the cap. But any pointy tool will do. Just go easy. BTW — that well looks dry, doesn’t it. Good thing I opened the cap.
4. Put in the oil. Don’t overfill, or you will squirt out oil when you put the cap back on.
5. Put the cap back on. Now clean around it if any oil spilled. Rubbing alcohol will do — the higher the alcohol content the better. Acetone will do as well. I suppose even soap and water. You just want the label to stick again when you are done.
6. Reseal the label and re-mount the fan. Be sure to check again in a few months.
In conclusion, I will repeat:
Lubricate every fan that can be lubricated before you install it, and re-lubricate it just as you would your car: with proper treatment a sleeve bearing fan might last a long time. And a ball bearing fan will run more quietly.
I showed you how. It’s quick and easy. Do it and you’ll be happy you did.