I was given a 90's Specialized Epic Carbon as a gift. It is 7 speed with Shimano 105 components. The cassette was dirty when I received the bike so I decided to take it apart and clean it. Upon reassembly, the cogs can wiggle on the freehub body when tightened to spec (40 NM or 30 ft lbs) . Unfortunately, I don't remember if they were loose to begin with. The cassette is a Shimano hyperglide possibly model hg-70. (hg manual here). I don't seem to be missing any parts or have any leftover sitting around. Does this mean my cassette is worn and needs to be replaced, or am i doing something wrong?