Back in 2006, our ancient (19-ish years old) Whirlpool refrigerator started making weird howling noises suggested someone broke into the house and stuffed a dog inside the freezer. Turned out to be the fan behind the rear panel of the freezer compartment that moves air across the cooling coils and down into the refrigerator compartment; evidently the sintered bronze bearings wore just enough to let the shaft oscillate side-to-side while rotating.
I ordered a replacement, but then decided to try an old fix: put a dollop of STP in the bearings. That added enough damping to kill the resonance and let the old fan turn freely. It worked so well that I put the new fan on the shelf in case it came in handy later on.
Years passed… and then, as if by magic, the freezer dog reappeared.
Mary moved the contents to the downstairs chest freezer (she’s much more organized than I and wanted to find things again), I pulled the old fan out, installed the “new” fan, buttoned up the freezer, and it ran fine.
Until about two in the morning, when the freezer dog began howling again…
As nearly as I can tell, the new fan’s bearings arrived just slightly oversize; I doubt they’re pre-worn.
So I applied the STP fix to the new fan:
- Remove the compression fitting from the fan blade hub
- Remove the fan blades from the shaft
- Remove the screws & nuts holding the frame together
- Remove motor shaft from bearings
- Put a drop of STP into the rear bearing
- Slather a ring of STP around the front bearing
- Deliberately misalign the self-aligning bearings to redistribute the slack
- Reassemble in reverse order
It’s been running silently for a day, which suggests it’ll be good for quite a while…