We recommend a transmission fluid change.

A transmission fluid change is a "drain-and-fill" method, replacing 30%–50% of the fluid and usually the transmission fluid filter, which is safer transmission service.

A transmission flush uses a machine to remove 100% of the old fluid, including from the torque converter and cooler lines, offering a more complete cleaning but has potential risks for high-mileage transmissions that have not been serviced.

Transmission Drain & Fill Fluid Change

  • Process: Drain fluid via gravity from the transmission fluid pan; usually replaces ~40–50% of total fluid.
  • Pros: Less expensive, gentle on older transmissions, usually includes a transmission filter change.
  • Cons: Leaves a significant amount of old fluid in the transmission, requiring more frequent transmission fluid services.
  • Best for: High-mileage vehicles, vehicles that have skipped previous maintenance, or as general maintenance.

Transmission Flush

  • Process: A machine pushes new fluid into the transmission cooler lines while forcing old fluid out, replacing almost 100% of the transmission fluid.
  • Pros: Cleans out nearly all old fluid and contaminants.
  • Cons: More expensive, risk of dislodging debris in transmissions that have not been regularly serviced.
  • Best for: Regularly maintained transmissions, following the vehicle manufacturer's recommendation.

When to Choose Which Type of Transmission Fluid Maintenance

  • Never flushed the transmission before? If the transmission has high mileage (+100k miles) and has never had the fluid changed, a drain and fill fluid change is safer.
  • Regular transmission fluid changes? If standard transmission fluid maintenance intervals (every 30,000–60,000 miles) have been done, a transmission fluid flush is acceptable to keep the transmission clean.

If you are unsure, do a transmission drain and fill service.