This tension roller maintains belt tension in the threshing drive of the parent combine. It is mounted on a pivot arm and presses against the belt to prevent slip under varying load from the threshing drum. A seized or worn bearing in the roller causes belt flutter, which leads to uneven drum speed and reduced threshing efficiency. The roller is manufactured to the original diameter and width specification so that it maintains the correct belt wrap angle without requiring shimming or bracket modification. When replacing, ensure the pivot bolt is torqued to specification and that the belt is aligned to the roller face.