How Tight Should A Serpentine Belt Be. The required measure of tension in the serpentine belt is that it should not deflect more than ½ inch when twisted either way from the middle. I will usually tighten it up till i have a 1/4 inch deflection in the belt.
If twisted more, the belt is loose, and if twisted less, the belt is. The belt should have about a half an inch of play when at the appropriate tightness. If twisted more, the belt is loose, and if twisted less, the belt is too tight.
