Oiling Bathroom Exhaust Fan Motor.

[George7941]

Air King BF15. It is an old fan , now obsolete and with no parts available, according to the manufacturer.

3000 rpm shaded pole skeleton motor with sleeve bearings. Wall mounted fan with the motor shaft horizontal. The motor was producing a whining sound from the bearings and also generating a bit of rattle. A little surprisingly, the noise only occurred when the motor was powered, the noise disappeared as soon as the switch was turned off, even though the motor was still spinning. I applied some oil (ATF) to both bearings and that eliminated the noise and the motor sounds normal again.

I have since found this motor which should work and I will replace the motor next time.
http://www.alltemp.ca/product-finder/product?part_num=T1-R3670

My question is, how long will the oil last?

 

[dlundblad]

How long will it last? Good question. ATF isn't a grease so we shall see..

Exhaust fans aren't that expensive. I bought one for less than $50 a while back for a family friend.

New fan with a warranty. Just seems like less hassle.. assuming you can find one to fit the existing hole.

 

[EdwardC]

I'd be curious how a thicker grease compares to the ATF. I'd be tempted to try that once it starts making noise again, see if it lasts an acceptable amount of time before top ups

 

[BigCahuna]

I had a thru the wall kitchen exhaust fan that seized up.I was surprised by checking around the internet, there was a place that sold them a mile from the house. It cost $60 and has been working fine for almost 10 years. If you can read the info printed on the motor of those types of things, alot of places can cross reference it to a new motor if you need one.,,,

 

[George7941]

It isn't the expense of a new fan, it is that the drywall has to be opened up to fit a new fan in because the duct connector sticks out a few inches from the housing and the connector, attached to the top of the housing, has to be slid into the vertical rigid exhaust duct. I will just replace the motor the next time the fan becomes noisy.

 

[onemig]

From what I have read from the interwebs, the best lube for electric motors especially for furnace motors is this: SUPCO GIDDS 461354 Zoom Spout Turbine Oil.

There are many other brands too for this type of oil.

 

[George7941]

Originally Posted By: EdwardC
I'd be curious how a thicker grease compares to the ATF. I'd be tempted to try that once it starts making noise again, see if it lasts an acceptable amount of time before top ups

It is tough to get grease in without completely disassembling the motor. Also I think grease is the wrong lubricant for bronze bushings.

 

[George7941]

Originally Posted By: BigCahuna
I had a thru the wall kitchen exhaust fan that seized up.I was surprised by checking around the internet, there was a place that sold them a mile from the house. It cost $60 and has been working fine for almost 10 years. If you can read the info printed on the motor of those types of things, alot of places can cross reference it to a new motor if you need one.,,,


Printed on the motor is UPPCO 57. Googling did not bring much up. There is a used one on e-bay.

The motor I linked to in my first post seems to be the best to use when it becomes necessary to replace the motor.

 

[WhizkidTN]

FWIW: I replaced my two fan motors for ~$20 each a couple years back. Made a YUGE difference in the sound and function (the original ones were ~20 years old).

 

[JamesBond]

I clean and lube my Honeywell fan every 6 months or so. It's an 8 in. plastic fan that I run in my bedroom 8-24 hrs/day.

The first time I cleaned and oiled it was because it was slow and would barely start on its own. With regular maintenance it should last a long time.

Take the motor out and oil the felt pads around the bearings. I use 3 in 1 electric motor oil or whatever is in the zoom spout oiler.

 

[oilpsi2high]

Use ball bearing oil made for rc cars.

 

[mjoekingz28]

Originally Posted By: George7941
I will just replace the motor the next time the fan becomes noisy.




Is this because of it being a hassle or a fire hazard?

Consider that some of the old stuff can go on for ages -if maintained. Maybe it hasnt gotten oil in a while. So, maybe everytime it starts making noise- oil it again.....but dont over oil it. I do not quite understand WHY, but it IS possible to OVER oil some things.

 

[George7941]

Originally Posted By: mjoekingz28
Originally Posted By: George7941
I will just replace the motor the next time the fan becomes noisy.




Is this because of it being a hassle or a fire hazard?

Consider that some of the old stuff can go on for ages -if maintained. Maybe it hasnt gotten oil in a while. So, maybe everytime it starts making noise- oil it again.....but dont over oil it. I do not quite understand WHY, but it IS possible to OVER oil some things.


The fan is not mine but belongs to a friend of mine who lives 30 km away.

I am not expecting the oil to last since I think there is now play between the shaft and the bearings because there was a rattling sound before oiling. I did not feel any play when I pulled the motor assembly off and checked for play before oiling. There was some axial play (normal for sleeve bearing motors) but no discernible radial play.

If the fan stays quiet for a couple of years then I will renew the oil next time. If it becomes noisy sooner I will replace the motor.

 

[PandaBear]

Did that to a humidifier fan before. It stays quiet for 1 day with 10w30 and then becomes noisy again. I suspect the bearing is worn and no oil will be able to fix that for long, or the oil / grease will be too thick and makes the motor winding runs hot and burn out.

Not worth it IMO.

 

[ecotourist]

Your message was very timely. We just finished renovating a bathroom and within a few days the fan started making a lot of noise. I wondered about putting a drop of oil on the only accessible bearing and your message prompted me to do it.

The result - the noise is gone and the fan seems to be turning faster as well.

I used "Masters Lubricating Oiler" recommended for bearings and moving parts of pumps, motors, fans, compressors, etc. It's quite old; I've used it in the past on furnace fan motor bearings. Seems like about a 20 or 30 weight oil. We'll see how long this lasts.

 

[NJ_Car_Owner]

I swear by SuperLube synthetic oils and greases. It comes in various forms - a spray, oil and grease. I do not like the dry film version at all but the normal stuff works great; it is H1 rated for food contact once things "dry up". The only thing I have not been impressed with it is lubricating car door hinges and I think it's because spray lithium grease can get pushed into crevices where the SuperLube is much thinner when sprayed on.

For what you are using it for you can try their oiler pen as it can give drops to a specific area.

My first experience with it was spraying down house door hinges and after using it my doors would open by themselves because they weren't level.

 

[DBMaster]

Originally Posted By: onemig
From what I have read from the interwebs, the best lube for electric motors especially for furnace motors is this: SUPCO GIDDS 461354 Zoom Spout Turbine Oil.

There are many other brands too for this type of oil.


+1. This is what I used for my bathroom exhaust fan that had nearly quit spinning and it has been fine for months. I purchase HVAC parts for a living and this is what my employer sells to techs for use on motors. The pull-out spout on the bottle makes it very easy to get the oil where it's needed.

 

[JTK]

Problem is, how do you get to the bushings/bearings on the vast majority of these motors that aren't designed to be taken apart?

 

[DBMaster]

It's not easy at all. The Zoom oiler bottle can often make them reachable due to the long, flexible pull-out tube built into the bottle. It's literally made for oiling motors.

 

[George7941]

Originally Posted By: JTK
Problem is, how do you get to the bushings/bearings on the vast majority of these motors that aren't designed to be taken apart?

I dripped oil on to the side of the bushing that was accessible and on to the shaft itself next to the bushing. It has been a couple of weeks since I oiled the motor and it is still quiet. The oil did the job.

Waiting to see when the motor becomes noisy again.