[alltaken]

My mother has a 35 year old electric Sears Furnace. It heats fine, but the fan (or something) makes noises and perhaps a heavy vibration in the plenem (spelling) for a couple of seconds on start up, then appears to run smooth and balanced in the heating phase. When shutting down, the nosie starts up again making a dit, dit, diiittt, ddddddiiiitttt, sound as the fan slows to a stop.

When I open the access panel and manually spin the fan it makes a dragging sound as if the fan is dragging on the housing as some point around it's circumfrance. So I do not suspect the motor itself. Perhaps the fan bearings are failing and causing some unbalanced rotation at slow speeds.

1. Thoughts on the diagnosis?

2. Where can I get parts for such an old beast?

3. How would I go about fining someone knowledgible and capable to repair this old furnance. Or should I just do it?

[alltaken]

12 people have viewed this post and no one has any ideas or thoughts?

[ernesto1959]

If the unit is 120 V , may not use a capacitor, but put current off, take away the whole fan casing and pull the wheel , motor and take it to the motor marketier , he will match it.

[ernesto1959]

If you are in south california (LA, to Riverside ) I can do all the job.

[icehouse]

Sounds like the bearings in the blower wheel are shot.

[alltaken]

Originally Posted by ernesto1959

If the unit is 120 V , may not use a capacitor, but put current off, take away the whole fan casing and pull the wheel , motor and take it to the motor marketier , he will match it.

Why would you suspect the motor to be bad? It runs fine. It is the blower wheel making the noise.

I have seen seen where I can purchase PT# 601211 from ********************************.com, but am not sure the bears will come with the part.

[alltaken]

Thanks for the reply. You are on my page, in thinking it is only the bearings. I found that I can purchase a blower wheel from ********************************.com, but not sure it would come with bearings. I called them and talked to a lady. Not to be sexist, but she knew less about this stuff than I do and had zero mechanical sense. So getting the information I need is tough. Do you know if blower wheels typically come with the bearings? For $80, I suppose I could just risk it and order the wheel.

[icehouse]

Model # 867.587751

Part # 601211


Make sure you grab the motor shaft and move it around. This will check motor bearings.

[daniel_bingamon]

I had one of these furnaces, mine a Sears 867.758180 series.

The motors are oilable and supposed to be oiled once a year. The back bearing gets loaded with crap and dries out. If you loosen the screws and split the motor shell and pull back off just a little bit, you can then spray a penetrating oil first (like Kroil) and once it freely pivots put some motor oil on it. This will work for a year before it needs another oiling, there are little cups on the motor and they should be mounted on top - I think some motors were not mounted in the right orientation by the maker.


I did this for a about 10 years and one time I waited too long the motor gave up and finally bought an AO Smith motor from Grainger but I had to reverse the fan blades (physically bend them) since their motor turned the opposite direction.

[hvac_hillbilly]

Word Of Advice The Dust Build Up Is What Put Blower Out Of Balance Cleen The Wheel Real Good I Like Coil Cleaner And Water House Take Care Not To Get Motor Wet Cause It Will Short Out So Clean The Wheel And Replace The Motor And It Will Run Like New A THE BEARINGS HAVE TO MUCH PLAY IN THEM THAS WHY YOU NEED TO REPLACE THE MOTOR