Blower motor buzz

[PbFut]

I have a faint metalic buzz in the original 72 AC blower motor. All speeds
Duct work seems to amplify some and bugs me. I oiled bushings/bearings using 50 year old 3 in 1 oil. Had to keep authentic.
Has anyone experienced and found solution?

[HO455]

Try testing the motor without the blower blades. It's possible the blade assembly may be causing the noise.

Or maybe some debris in the heater box. It's real common to have junk in the heater core area.

[PbFut]

motor out and fan is off the motor.
Yes lots of rat/mouse stuff last year. All cleared last year and has remained good and clean. The sound is for sure from the electric motor. It is off the truck and on the work bench as I attempt to repair. Motor does not appear serviceable. Its not a bad sound like the motor is dying. I think the motor is good for a long road ahead, but the buzz, though faint is annoying to me.

[RustyPile]

Old 3 in 1 isn't my 1st choice but it will probably work.. I use electric motor lubricant.. The bearing under the fan is easy to lubricate, the bearing at the other end, not so.. Drill a small hole in the "bump" at the end of the housing. Put a few drops of oil through the hole, and seal the hole with epoxy....

[PbFut]

With the vent tube off the motor, I can easily see the rear bearing area inside the case and did oil the shaft and allow to soak the area. I will drill as very last resort. Thank you for suggestion. I hate to damage as it is a really good condition housing, original factory 1972 unit that otherwise works perfect and looks pretty good. Some surface rust rash in small areas.

[leddzepp]

Originally Posted by RustyPile

Old 3 in 1 isn't my 1st choice but it will probably work.. I use electric motor lubricant.. The bearing under the fan is easy to lubricate, the bearing at the other end, not so.. Drill a small hole in the "bump" at the end of the housing. Put a few drops of oil through the hole, and seal the hole with epoxy....

X2. Have done this on several trucks. Works like a charm.