Can a ply be broken on a leaf spring?

The correct answer is that the main leaf of a leaf spring may not be broken. This is due to its critical role in supporting the vehicle's weight and maintaining proper suspension geometry. The main leaf is essential for the structural integrity and performance of the suspension system. If this leaf is broken, it can lead to a failure of the suspension, compromising vehicle safety and handling.

In contrast, while secondary leaves may have some tolerance for minor damage, any breakage in the main leaf can significantly impact the safety and functionality of the vehicle. Therefore, maintaining the integrity of the main leaf is crucial. The other options suggest scenarios where the main leaf could be compromised or imply that all parts of the leaf spring could fail without consequences, which does not align with safety standards and inspection criteria.