Explain this?

[DGreimel@aol.com]

Fellow listers,
Perhaps one of you engineer types could explain why a ring of large allen 
screws that hold the left side axle flange to the differential on my BMW all 
backed out and left me without motivation.  They were all still there and 
only one was bent.  There was absolutely no warning.  It just would not move 
when I wanted to move off from a traffic light 20 miles from home.  The 
flange would normally rotate counter clockwise looking at the bolt heads.
Thanx
Don