👉 A truck's fluid, commonly known as transmission fluid or transmission oil, is a vital lubricant and coolant that circulates through the vehicle's transmission system. It serves multiple purposes: it reduces friction between moving parts, preventing wear and tear, and dissipates heat generated during operation to maintain optimal temperature. Additionally, it helps to transfer power from the transmission to the differential and driveshaft, ensuring smooth and efficient gear changes. Different types of fluids cater to specific transmission types, such as automatic or manual, and are essential for maintaining the longevity and performance of a vehicle's transmission system.