Carl,
Is it because it allows it to swivel slightly?
Chris
It would be able to swivel if the pivot point were a single short bolt. But they're usually about 3 or 4 inches long, which restricts the movement only around the bolt. With the turnbuckle perpendicular to the axis of the pivot bolt on the opposite end of the generator/alternator. It can't move sideways. It's all about restricting the degrees of freedom. A long bolt takes care of two directions, and the third is taken care of by the turnbuckle or the standard adjusting strap.
