The short answer is that this can be done, and, in fact, there are kits available to allow you to add a leaf to a suspension spring-pack. The broad idea is to make the spring stiffer, increasing ...

Shackles are a vital part of a leaf sprung suspension. Flexing of the elliptically-shaped leaves changes the straight line distance between the spring pack's mounting eyes. A shackle is placed at one ...

It is said that the leaf-spring suspension is the oldest suspension used for automobiles. The leaf-spring system was used more recently in '70s production cars, some of which are still in service ...