Rotary tool, polishing compound, rags, Q-tips, more rags, medium and soft bristle brushes for rotary tool, simple green for clean up, Main gear for the ABU 5501 and Pinion gear for same. Clean all parts of grease and oil. Dry well. Secure hair bit in rotary tool medium. Coat main gear with polishing compound, light coat is all that is needed. Simichrome is great for this application. Start in the inside of the main gear along the edges being careful to keep your tool moving at all times. work tool back and forth until the compound turns black. Move to the teeth of the gear and getting into each valley. Turn over and polish the bottom of the gear. Clean with soft cloth and a tooth brush for the teeth. Simple green the whole thing. Mount the soft bristle brush and repeat the whole process again. You will know when it is enough when after the clean up you have a mirror finish. Pinion gear needs a little help. I mount mine in the end of a sharpened pencil to hold it. Press it down and shape the pencil to hold it the best you can. Medium and then soft bristle to a mirror shine. Grease your drag plates and gears with a light coat of Cal’s and reinstall. Smooth, no jerky drags and the gear engagement is sweet and butter smooth.