What would cause chipped and broken inter-axle differential lock clutching (dog) teeth?

Shifting the inter-axle differential lock during wheel spin can lead to chipped and broken clutching (dog) teeth due to the sudden engagement or disengagement of the locking mechanism while there is a difference in wheel speeds. When the inter-axle differential is locked, it connects the front and rear axles, requiring both to rotate at the same speed. However, if one wheel is spinning faster than the other—commonly seen during sudden acceleration or when traction is lost—the teeth on the clutch can endure excessive stress as they attempt to engage or disengage under those conditions.

This abrupt transition can cause mechanical failures, including chips or breaks on the clutching teeth, which are designed to mesh smoothly. In essence, the mismatch in rotational speeds creates a situation where the locking mechanism experiences extreme loads, leading to physical damage. Proper operation dictates that the differential lock should only be engaged or disengaged under suitable conditions to avoid this type of wear and damage.