I just got some THK HSR20 linear bearings from Ebay. They are a pair of 48" rails and 6 trucks. However, they appear really dirty and sticky. If the rails are held vertical the trucks will not slide down. It does not appear to get any better if they are loaded (ie the trucks are not preloaded). They have a really sticky black grease on all over them that appears to be gumming them up. My question is how do I go about cleaning them up??? I think I can carefully take the trucks off and clean the rails and the trucks without losing any balls as they are not caged. Is this a good idea???
Also, the Ebay listing said good condition and after carefully sliding one of the trucks off it appears that some of the balls are missing. I don't think it will make a difference, but should I say something to the seller anyway. The bearings still seem extremely rigid on the rail, just a little sticky.