I have a 2008 c300 4matic with about 45,000 miles. All of a sudden there is a winding noise coming from what seems like the tail end of the transmission. I had it up on the hoist at a local mechanic but having never worked on one he didn't want to start trying things. There is absolutely no loss of power or anything noticeable in the handling. The only issue is a fairly loud noise that sounds like something is winding up. Any ideas would be much appreciated!