ball bearings.

[tp4tissue]

are you not suppose to oil ball bearings ?

Everytime Tp4 does it, they start to make this tongue clicking noise, like grrrrrrr.... tshch..tshch...

how do get into the tiny sealed fan bearings without breaking the metal cover ? it's not the rubber covers which goes back easy.   This is why tp used the oil in the first place, can't get those covers off without breaking them,  is it supposed to be grease only ?

[Darthbaggins]

normally ball bearings use a grease to lube them over time.

[Leslieann]

Depends on intended use but almost all use grease.
The metal shields are usually either press fit or c-clip and won't come off without damage.

Most (if shielded) are considered expendable and not intended for rebuild and if it runs rough, regardless of lube, it's toast.