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?

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 :o the motor marketier , he will match it.

Sounds like the bearings in the blower wheel are shot. :)

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 Searspartsdirect.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.

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.