How Often Should Transmission Fluid Be Changed in a Family Sedan?

[DeAdalynn]

For family sedans with automatic transmissions, the automatic transmission fluid should be changed every two years or every 40,000 kilometers driven. For manual transmissions, the fluid should also be changed every two years or 40,000 kilometers. Different vehicle models may have varying requirements, and the car's user manual indeed specifies that transmission fluid needs to be replaced at regular intervals. Methods for changing transmission fluid: 1. Loosen the drain plug at the bottom of the transmission to drain the old fluid before refilling. 2. Remove the transmission oil pan directly to drain and refill the fluid: This method is more thorough than the first one, as it allows for the removal of impurities settled at the bottom of the oil pan. 3. Use a circulation machine to change automatic transmission fluid: A smart circulation machine enables dynamic fluid exchange, filtering and cleaning sludge and impurities inside the automatic transmission. Functions of transmission fluid: - Reduces friction and wear, controlling clutch friction and synchronizer performance. - Bears loads (low-speed high torque, vibration loads), dissipates heat, reduces vibrations and noise, and cleans contaminants at gear meshing points (cleaning function). - Prevents corrosion, pitting, and surface metal peeling, isolates metal surfaces, and prevents direct metal-to-metal contact.