Harman Accentra FS distribution blower started squealing

The OEM ebmpapst blower started to squeal, seems to be coming from the outer rubber blower mounts. There's a pinhole in the center, is this for oiling?
It squeals on and off in different amounts of time, strange!

 

Think I'd pry out the rubber thingie and see what is under it and if a bearing, oil it with light machine oil. You have the old one correct? Take that one apart.

 

Didn't buy another one, making do with the original.

 

Yes, I'm guessing that IS an oiling hole. Squirt some light oil in it (3 in 1 will work).....can't hurt anything.

 

Think I'd pop the cover and have a look-see anyway.

 

Nylon sleeve inside

 

Yes, the rubber holds a bushing, as all tangential blowers do. The bushings are some sort of plastic. Older units, like Austroflamm, had bronze ones.
Also, with time, the motor side will get tight in the bushings. The old grease/oil will burn, and create a hard buildup on the shaft ends. They really are not that hard to totally disassemble. Clean the shaft ends, and inside the bushings with carb cleaner, alcohol,toluene, whatever you got strong laying around, and a scotch brite pad or fine steel wool. Oil with anderol 465, or synthetic light oil,even car oil.
Pro tip, oillite bushings are made to be immersed before installation. What I do is block one side off, good tape works, fill with oil and let sit for an hour or so. Actually that is straight from manufacturers, and a good thing to do IF you have motor disassembled.
Another pro tip- the tangential "wheels" are easy to bend, disassembling, bumping with vacuum cleaner,etc,, and also, the bushings can get worn, a bit loose. This can set up a harmonic, giving a slight rumble. Set on bench. Spin up the blower wheel with air pressure. Before installing, to test. If vibrates you can easily see, and correct by slightly bending,tweaking the wheel, and give new quite life to such blowers. Cleanliness is next to godliness, should not have to say, but a coating of dust on all the little vanes, that does not blow off or vacuum off, can reduce your air flow by 30%. Dish soap and hot water is your friend. Just wipe a vane with a finger, should be squeaky clean.
OK, that's some tips for the day.

 

If I was gonna pre lube any oil lite 660CA impregnated bushing, I'd tape the end, fill it with light machine oil and put in a toaster oven set on medium temperature and allow the oil to capillary in. In fact that is how I lube my bushings when dry.

You can replace the bushings with skate ball bearings as well.