To adjust a belt drive, slacken the pivot bolts and slotted straps, make the adjustment, and then tighten the bolts and straps. Some cars have idler-wheel pulleys with screw adjusters for adjustments. This makes the belt easier to adjust than in the traditional way.
To adjust the drive belt in detail, it is necessary to loosen the bolts and strap so that the generator moves freely. It is best to loosen the pivot bolts on the generator first, and then loosen the bolts on the adjuster strap. At this point, the adjustment of the belt can take place.
To begin the adjustment, tighten the belt by pulling the generator from the engine with a strong piece of wood, such as a hammer handle. While doing this, use the other hand to test the belt tension. When the tension is right, hold the generator and tighten the strap bolts into place. Recheck the tension at this point, and if it is correct, tighten up the pivot bolts.
To add slack to the belt, start by loosening the pivot bolts only enough so that the generator is movable by hand. Manipulate the generator with small movements while continuously checking the belt with the free hand. When the tension feels correct, tighten the strap bolts, and then tighten the pivot bolts.