Car owners need to change their transmission fluid at the intervals specified in their vehicle user manual. Do you need a fluid change or a transmission flush? The two terms aren’t interchangeable, and most auto repair services offer both. We’ll explain the difference.
A fluid change is more generally known as a transmission service. Under this process, a mechanic replaces the filter and drains the pan. However, not all of the fluid drains out. Some still remain inside the cooler lines and torque converter. As such, the new replacement fluid mixes in with the old. A mix of new and old oil, though, is still better than running purely on the old fluid.