You have to open the motor to check, some wicks are still fine, but some are clogged up with hardened grease. The black bakelite screw on top are for the carbon brushes. When you open the motor , it will come appart, there is this small agular bit that lies in top of the motor (between the casing and the internal motor parts). It gives just the right spring action and keeps the parts stable. The ends of the turning part can be given a bit of grease directly, and yes, the wicks can only be checked from the inside. The motor is kept together with long screws with bolts at the end. The last motor I took appart was the later type with out the grease wicks, and I can't remember exactly the old motor on my 99 was. The grease wicks can have a metal cap on one side, some seem to have a spring coiled around the end. Some prefer the old motors which took grease, because they ran very nice and noislessly. Some of the later motors had a bit of a whirring sound in comparison, but there were several versions of these motors with smaller variations.