I have ome old Shimano SPD 747 pedals. I've used them for years and even though they've been through quite a bit of beating I've never taken them apart. What I mean by takeing htem apart is that I want to remove the axle from the body and clean and lubricate all bearings and then reseal it nicely. Does anyone know how to do it. I know that on SPD 535s ther is a lock nut on the outside of the pedal that can be unscrewed and the pedal can be worked on. 747s don't have such a nut. What's a good way to approach this issue?