What does improper transmission fluid maintenance typically lead to?

Maintaining proper transmission fluid levels and quality is crucial for the health of a vehicle's transmission. When transmission fluid is not changed regularly or is contaminated, it loses its effectiveness in lubricating the internal components, which can lead to increased friction and heat buildup. This overheating can cause the parts to wear prematurely, resulting in costly transmission damage. Additionally, old or low fluid levels can cause erratic shifting, slipping, or complete transmission failure, necessitating significant repairs or a full replacement. Therefore, neglecting transmission fluid maintenance directly risks the functionality of the transmission system.