Seemingly the most common self-inflicted injury suffered by BX Kubotas is a broken trasnmission fan by running over a branch. The fan is plastic, unprotected, is a $ part, but costs $$$ to replace because, depending on BX model, requires the removal of many large components.
Prevention is better than the cure, which is why a Rear Skidplate is the first "implement" purchased by many BX owners.