Ive got a 2001 chevy s 10. when I shake the box side to side there is a clunking sound comeing from the axel. it sounds like the wheel is not tightend down but it is. any ideas

 

Not a concern.
It is just a small amount of play in your axle. The sound it makes is accentuated through your wheel and brakes.

Next time your in a parking lot, ask anybody with a S10 or S15 if you can shake their vehicle... Theirs will do the same as yours.