The blower motor was "chirping" in my truck, so I took it out expecting to find the box full of debris.

Nope.

But spinning the squirrel cage showed the bearing/bushing to be dry. I sprayed it silicone lube and all was great- for about a week. Now the chirping is back, indicating that I need a better lube. What works best, and preferably not some special one-use-only type product?

Thank you!

can you source a new bearing?

I'd use a small dollop of grease out of your grease gun

Those are sintered bronze bushings and they will generally hold oil within. Also you'll notice a felt pad in close proximity to the bushing. This is what you should be lubing. The bushing will draw the oil as needed from the felt pad. Personally all I've ever used (and I've done a lot of different motors) is plain old motor oil. If you use oil that's too thin it just runs down the ends of the motor and does no good after a short while. Thicker oil stays in the pad and bearing.

Those bushings generally aren't replaceable. First, they're held in with a spring washer of sorts that you'll scrap trying to get out. Second, the bushings are usually oval shaped so that they'll self-align.

Oil it up good and I think you'll be good to go.

FWIW I never grease a bronze bushng, they're meant to hold oil. Grease is for bearings.

Thank you everyone!

Noted

Replace the thing.

If it didn't work, of course.

But since it works fine other than needing lube, I'll simply fix it.

Rarely will re-lubing work long-term once the bushings are damaged.

Who said the bushings are damaged ?!?!?!? Bushings dry out all the time.

Bushings are easy to check if they're bad ...

a) is there significant side play? yes = bad no = go to b)
b) is the shaft seized or hard to turn? yes = oil it

I hope it works out for you. It would be nice if a little lube did the trick. If I were dead set on lubing those small bushings, I'd use synthetic disc brake grease. Fill the bushings with grease, put them inside a small assembly of galvanized pipe parts that make up an air tight container and pressurize the galvanized pipe with compressed air to drive the lube into the bronze.

I used to pre-oil my pilot bushings by placing the bushing on my palm, filling it up with oil and capping the top with my thumb. I would try to compress the oil by pushing down with my thumb until I saw it weeping through the bushing.

hmm, an oilite bushing needs lube

OILite bushing, wonder what lube you should use in an OILlite bushing.

Grease? Oh sure that's what belongs in an OILite bush.

30w is typically what is used.

https://en.wikipedia.org/wiki/Oilite

http://www.webcitation.org/5m66FprSI says " Can be re-oiled when dry
(submerse in SAE 30 motor oil for 72 hours at room temperature to replenish"

"oilite" ... duh !!!

And the pressurized pipe thing is hilarious too! Unless you fill the entire pipe cavity with your "grease", nothing's going to happen. And even if you did, the possibility of the grease pushing out the air in those minute voids in the bushing is slim at best. If you were to fill the cylinder with light oil and the bushings were submerged and the cylinder pressurized, MAYBE it would work but the same results can be achieved with a good soaking.

But as I said in an earlier post, soaking the felt pads around the bushings will do the trick.