Why Does the Car Lack Power After Changing the Transmission Fluid?

[DelEverly]

Slow acceleration after changing the gear oil is caused by overfilling the transmission fluid or air mixing into the system. Solutions: Check if the transmission fluid is overfilled. If the fluid level is too high, it will submerge the gears. When the car starts, the gears have to overcome the resistance of the fluid, leading to power loss. Additionally, the agitation of the gears causes the fluid to foam, introducing air into the oil circuit and reaching the clutch. When shifting to D gear, the presence of air between the clutch plates prevents them from pressing tightly, requiring re-filling. If the fluid level is correct, the issue may not be the fluid—check the clutch, as it could be the problem. Transmission Fluid Replacement Methods: 1. Loosen the drain plug at the bottom of the transmission to drain the old fluid and refill. 2. Remove the transmission oil pan directly for draining and refilling. This method is more thorough than the first, as it removes impurities settled at the bottom of the pan. 3. Use an intelligent circulation machine for dynamic fluid replacement, which filters and cleans sludge and impurities from the automatic transmission through a circulating process.