Ive seen belts go at anywhere from 40k upwards for a wide variety of reasons mostle caused by ancillary componants,ie tensioner idler pullys,oils starvation you name it,including speed bumps and bump starting.Given the cost invloved i recomend intervals of no more than 4 years or40k.That may sound like a con to you but i make a hell of a lot more money out of you if it snaps.The best advice for longevity is top quality belts,renew all rotating parts associated and adjusted using correct messuring equipment to assess/adjust tension
caine
August 2008
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