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RE: Self-Tightening Lug Nuts

Chris Pawlowicz wrote:
 
 > I often have my lug nuts tighten up by themselves so that I need a 
 > 2 foot cheater bar on my socket wrench to unfreeze them. I *know* 
 > I torque them correctly to ~85ft/lbs with a torque wrench, 
 > immediately after they are easy to remove, but a month or two 
 > after and UGH!
 > Don't know why they freeze by themselves but they do.
 
Chris,
 
You don't say where you're located, but I'd have to deduce that you live 
somewhere in the northern hemisphere.
 
People used to attribute this tightening to rusting of the lug nuts to the steel 
wheels.  However, it's only since mag wheels have become commonly used that 
automotive engineers have realized the phenomenon can no longer be explained 
by rusted lug nuts, and have discovered the real reason.
 
The spontaneous tightening is caused by the Coriolis Effect.  It is well 
known that the Coriolis Effect is responsible for the clockwise rotation of 
ocean currents (and bathtub-drain vortices) in the northern hemisphere, and 
counterclockwise rotation in the southern hemisphere.  I'm sure our 
southern-hemisphere digest members will confirm that all BMWs delivered to these 
areas are equipped with left-hand-threaded studs/nuts to preclude spontaneous 
_loosening_ of their lug nuts.
 
Sorry.... I couldn't resist. ;-)
 
 Regards,
 Jerry
 Arlington, TX (18-Jul-96, 19:37)
 '95 540i-6 spd