The dreaded Mavic squeal!!
Many Mavic wheel owners know that familiar noise, the high pitched squeal that happens when coasting. But what causes it? Is it the bearings? Not likely.
The nylon bushing squeals when it is dry. Mavic recommends taking the freehub off and lubing the bushing (with oil, I personally use chainlube) every 1500 miles or so.
So if this servicing hasn't been done with your freehub, you get the dreaded squeal. Also, if it hasn't been lubed properly it will wear out and you have to replace the whole freehub OR you can replace just the bushing. There are aftermarket bushings available on eBay. Just search for "mavic bushing" on eBay.
Mavic will never tell you that you can replace just the bushing as they want you to buy a whole new freehub for around $70.
So the next time your Mavic wheels start to squeal, remove the freehub and do some maintenance.