省时省力?... 主流换法是正时皮带，水泵，张紧轮系统（怠轮 if any）通通换，否则 no point 换正时皮带...

When the timing belt is replaced, other parts, including the tensioner, should be replaced at the same time. This is because these components wear out at essentially the same rate as the belt. For instance, the tensioner bearings could dry out or even seize.