I have a case fan that can be quite noisy. I can take the fan out of the case, peel back the sticker on the center to expose access to the bearings, and lubricate the fan. Thus far, I've been using a few drops of WD-40, but after a few days the fan makes noise again.
Obviously, I could buy a new fan, but knowing how to lubricate a noisy fan seems somewhat useful, as not all hardware hardware has replaceable fan units.
Does anyone know why the WD-40 only works temporarily, and what I should be using instead?