the cassette itself is brand new. its a shimano 9spd xt. the hub is a shimano 105. the bike is a few years old - 1999 model cannondale xr800. and i bought it used a few months ago (like the above post says). i dont have the bike in front of me but i think that it is the whole cassette that feels loose and not the individual cogs.
do you think that this problem could create other problems down the road? as long as my shifting holds and it isnt going to mess up my cassette or chain or wheel, then maybe i can deal with a little extra cogs noise...
the "cassette body" is the plastic cover on the hub itself? the lbs basically did a hub overhaul trying to figure out what was wrong. i am guessing that this would include the retightening of that bolt you suggested.
"These can be taken apart and a shim removed to reduce their bearing play, but it's not something that I've seen in practice much."
the lbs said they could replace the part of the hub they thought was loose without replacing the whole hub. they had some in stock and said it would cost like $25 with the labor.
i am going on a longish trail ride today. if i have any more problems i think i will just let them do whatever they think will solve it. -- unless someone on this forum tells me that their approach sounds weird or gives me some other advice.