Emerson 77646 making a rattling-clattering noise for half of every oscillating sweep- is this something that can be fixed at home, or do I live with it?

[Hannah Dannehy]

I just put this fan back into working order, and after running it in for several hours it works great. The washer-chatter has gone away, the blade spindown time has gotten longer, and the motor barely gets warm. But now it makes a clattering sound for half of every oscillation sweep. The noise starts after the fan has been running for a minute or two- before that, the fan oscillates with no noise at all. The fan also does not make this noise if you set the oscillating angle to zero, no matter how long you run it.

I've checked that the oscillator rod is seated in the blade hub by removing the gearbox, pulling the rod out a little, and gently pushing and twisting until it found the notch and popped right in.

Is this a problem someone recognizes? Is it as simple as not packing enough grease into the gearbox (if indeed I undergreased it)? Or is it something that would involve taking the motor parts to a machinist?

I'm sorry if this is a stupid question, but I would rather expose my ignorance online than ruin my freshly revived treasure.

[Anthony Lindsey]

it's hard to hear in the video but put your finger on the badge on the cage and make sure it isn't loose.  A loose badge will cause rattling. 

[Russ Huber]

If Anthony's suggestion doesn't stop the chatter, you may have to live with it. On at least 3 different Emerson rotor on shaft restores of mine in the past, I have encountered this chatter problem. I resolved the issue on 2 of them by having a machinist bore and brass sleeve the rear bearing surface of the rotor to tighter tolerance. The Emerson single shaft floating rotor bearing surfaces are front and back and open in the center of the inside of the rotor. It is cast iron bearing surface riding on a polished hardened steel shaft.  In one case, I swapped out rotors (changing wear tolerance) to get rid of the chatter problem. 

You can try adding straight 30 SAE into the bearing when its chattering and see if the chatter disappears temporarily. If so, there is your heads up.

Before.

After with pressed in brass sleeve. Chatter gone.

Edited April 26, 2023 by Russ Huber