That is a special bolt only used by Toyota. If you are replacing the serpentine belt, that is not the bolt to be using for turning the tensioner. There is another 19 mm hex bolt like jutting out for you to turn the tensioner. If tensioner is equipped with a damper, ensure the damper is not out of position restricting you from loosening the belt tension.
Sunday, March 6th, 2011 AT 3:23 PM