Try jacking up the front axle one side at a time, to see if the radiator/fan clearance changes due to frame twist while encountering non-level terrain. Just put a floor jack under one side at a time even with the spring, and lift that wheel a few inches off the ground. You'll be surprised at how much the frame flexes and how clearances change.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!