Improve Automatic Transmission Performance and Reliability

The transmission is shifting harsh or if the vehicle is high mileage (> 85K Miles) and is out of warranty, you may want to perform the following actions to assure long term transmission durability and improve quality of shifting. Total cost is under $200. This technique is much better than a "power flush" since it is easier on the transmission and will gently remove any accumulated contaminants that may be in the transmission. This procedure also replaces the fluid in the torque converter.


  1. Use teflon tape on the threads and screw the barbed fitting adapter(s) into the pump body.
  2. Cut a 4" piece of the soft tubing and use it to connect the hard tubing and pump suction barbed fitting on the suction side (IN) of the pump.
  3. Assemble the soft tubing to the barbed fitting on the pump output side.
  4. Wire the battery clips to the power leads of the pump. Observe proper polarity! Red is Positive (+) Black is ground or negative (-).
  5. Check the transmission fluid level and top up if required. Drive the vehicle for 8-10 minutes to warm the fluid.
  6. Park the car on a level surface and shut the engine down.
  7. Feed the hard tubing into the dipstick tube of the transmission, make sure it bottoms in the pan if possible.
  8. Attach the clips to the car battery and pump out 6 quarts or more of transmission fluid into waste container. Measure the amount removed.
  9. Replace the amount of fluid removed with new fluid.
  10. Drive the car for at least a week. Do this 3 times at weekly intervals. Longer intervals are OK.
  11. After the third oil change drive the car for one more week, drain the fluid and change the transmission filter, clean the pan and replace the pan gasket. Refill the transmission, drive the car then check the level and adjust as required.


  • If the car isn't a Lumina use this as a guide, your fluid amounts will vary.
  • The results you should expect:
    • Better quality of shifts and smoother overall operation.
    • Reduced transmission noise and slightly better fuel mileage.


  • Transmission fluid can be HOT enough to burn you, exercise caution.
  • This may not help in all cases.
  • Be careful. Don't work under the car without jack stands.
  • Dispose of the waste oil properly at a collection center (auto parts store).

Things You'll Need

  • Buy or gather the following:
  • 18-24 quarts of the correct transmission fluid for your unit.
  • 12v dc (cheap) fuel pump if you don't already have a pump.
  • Product Number: 15660G that is the one I used. ~ $60.00
  • 2 battery clips, wire to pump, red to red and black to black.
  • {{safesubst:#invoke:convert|convert}} PTFE or equivalent 1/4" hard plastic tubing. (hardware store)
  • {{safesubst:#invoke:convert|convert}} soft PVC 1/4" plastic clear tubing. (as used in fish tanks etc.)
  • With fuel pump in hand go to a local hardware store or auto parts store and buy the adapters (2) to go from pump NPT to barbed fittings to adapt pump to the tubing.

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