Fridigaire FFU20FC6CW0 Upright freezer howls

[natman]

I have a Frigidaire FFU20FC6CW0 upright freezer. It does not have an ice maker. It was purchased new in about 2005. It worked perfectly for several years, then we were transferred overseas. The house was rented out and at some point one of the renters decided not to run it and it was left unplugged for some years. We're back in the house now. I've decided to use it and plugged it back in. It works fine, and keeps the proper temperature. After a few weeks of running more or less silently it has started to make a loud howling noise a couple of times a day. This will last for about 30 seconds then stop.

Any suggestions? Is there anything that requires lubrication or adjustment that could account for the noise? Thanks!

[16345Ed]

You need to determine source of noise. Check fan motors...

[natman]

Given the intermittent nature (seemingly random 2 or 3 times a day) and short duration (30 seconds) of the sound, it would be difficult to be in position to diagnose the exact source. My *guess* is a dry bearing that's complaining when a motor starts, then stops once it gets up to speed, but that's just a guess.

How many motors are there? Is it possible to lubricate the bearings?

 

[robrdavis]

There’s just going to be one fan on that unit, inside, behind the evaporator cover. The condenser coil should just be a static coil running up the entire back of the unit on the outside. The noise SHOULD be coming from the inside, about 1/3 of the way up from the bottom of the unit. There is no way to get into the motor and grease the bearings. 
 

As long as your model number is correct, the part number for the fan motor is 5304436055. 
 

Replacement is fairly straight forward: unplug the unit so it doesn’t bite you.  
 

The back panel should be held in place with eight 1/4” hex head screws (two are longer and go into the middle of the cover, the other six are all the same size).

Remove the cover. (Be careful to not kink the thermostat line. Thermostat can be unclipped from the cover and the panel can be completely removed, or the cover can be just swung to the right, out of the way.)

Remove the two screws holding the motor bracket in place.

Unplug the fan motor.

Gently pull the fan blades from the motor shaft (insert a flathead screwdriver in the split at the shaft-end of the fan if it’s too tight). 

Remove the ground wire and separate the bracket (two more screws) to remove the motor.

MAKE NOTE AS TO WHICH WAY THE SHAFT IS POINTING THROUGH THE BRACKET TO SAVE YOUR SANITY WHEN REASSEMBLING!

Reverse order for reassembly. 

Enjoy peace and quiet. 

[natman]

Thanks for the write up, it looks very helpful. It'll give me something to do tomorrow.

[natman]

The good news is that it was fairly easy to R&R the fan motor. It turns out that it is quite possible to get access to the bearings since the fan comes apart with two screws. Just out of curiosity, what would be a recommended lubricant considering that the fan runs in a subzero environment?

The bad news is that the fan spun and ran just fine, so the noise is probably coming from the compressor. I suspect that the compressor motor IS inaccessible and the cost of replacing it will be more than the freezer is worth, given the cost of the part and labor which is probably beyond my skills and the cost of Freon tools which I don't have.

I remember when refrigerators / freezers were powered by separate motors that had lubrication cups, but those days are gone.

Comments?

 

[Vance R]

Those motors have non serviceable bearings. Lubing them only last a little while, then has to be relubed. For me, wish they would just go back to good bronze bushing with graphite.

[natman]

Are you referring to the compressor motor or the fan motor? My fan motor has bronze bushings which are easily accessible.

[Vance R]

Fan motor, seems like the newer bronze doesn't last as long. 

[natman]

That may be. You mentioned graphite, I can see how that would not be affected by the cold. I have lubricated other bronze bushings used at room temperature by soaking them in 5w motor oil. Any other recommended lubricants?

[Vance R]

The graphite is supposed to be impregnated into the bronze when it is manufactured.  Triflow works ok but like any other oil it will need to be reapplied. If you have had good luck soaking with 5 wt oil worth a try.