I got chastised for mentioning it, but you can lube them two ways.
2. you can shoot a little light oil on the bushing where the shaft comes out of it and drill a real small hole in that hump in the back center of the motor and get a drop or two in the rear bushing. (if you are not comfortable taking it all apart.)
That's a old used car trick we used to use at the dealership. A small squirt of oil through a small hole in the end can give you a quiet motor for years. tmm