The furnace blower motor is going to be working in very hot conditions so the type of lubricant you use is important.
Lubricant for fan motor.
Apparently wd 40 was the wrong oil to use.
Do not use any flammable lubricant such as oil.
Step 3 apply a light nondetergent household oil that is sae20.
It is now so far removed from the way most americans think it.
Step 2 lay the fan down on a flat surface with the exposed face up.
Never put wd 40 in any electric motor even if the rotor is stuck from filthy dried up lubricant.
Add no more than 1 to 2 drops at each oil port.
Whenever you have to lubricate an electric pump bench grinder or other electric motor don t pull just any oil off the shelf.
First find the point where the shaft is holding the motor and clean that area.
Then put in a few drops of number thirty oil on both ends of the aforementioned shaft sticking out of the motor.
Don t use automotive motor oil.
Then swivel the shaft and cleanup any excess oil.
It is excellent for smaller electric fan motors because it helps to reduce friction when there is a moving surface.
Instead you might look for a particular brand of lubrication which is right for your motor.
Afterwards you can oil the fan.
This lubricant oil is produced by liberty oil products and it is a 100 synthetic oil compound.
Fan maintenance it s important in this throwaway society to realize the value of maintenance.
It not only removes any remaining lube but it can melt coil wires the lightly coated copper wires twisted up in electric motors and cause an electrical short.
Plus it contains detergent.
Lubricate a box fan motor step 1 remove the front grill of the fan.
It s too thin for electric motors.
Grasp the blades firmly and lift slowly to remove them.