Marine grease is for the bearings, once they have been cleaned thoroughly. Grease the balls and the races well, as you reassemble the respective components. Also, its good for keeping threads slick and smooth, prevents galling and sticking. WD-40 will help you clean up parts, but some mineral spirits (Stoddard Solvent) will work great and is much less expensive, buy a gallon can and some plastic containers can be used for cleaning bowls. Soaking things will loosen up the grime and crud. The WD-40 can be used as a penetrant, but its not a good lubricant, its actually a water dispersant.

Bill