Tensioners, like any other part, don't last forever, and automotive technicians will be replacing more and more of them. A failed tensioner can cause the belt to break or fly off the drive, resulting in a breakdown. Often the cause is misdiagnosed as a belt problem, when in reality the tensioner should be replaced. DriveAlign Automatic Belt Tensioner OE Fit, Not Retrofit Gates DriveAlign tensioners offer precise OE fit for a wide array of applications.