Automatic trans. flush


Cost: $15



Automatic transmission without pan, exposing its metal filter

Procedure for changing the fluid and filter on a 4hp22 automatic.


Procedure with dip stick

  • 3 qt of ATF fluid.
  • Ramps or stands.
  • Allen wrenches and torx screwdriver.
  • Brake cleaner spray.

1. First raise the car up and place on suitable jackstands or ramps.
2. Place drain pan under and remove metric allen bolt in the center of the pan. Do this with the fluid warm, so it drains more completely. Avoid burning yourself on the fluid.
3. Remove the large nut holding the dipstick tube and move the tube back a 1/2 inch or so.
4. Remove the 6 perimeter bolts and brackets on the pan, making note that some of the brackets are angled for the corners of the pan. Lower the pan.

5. Clean the pan out with brake spray cleaner and clean the two rectangular magnets in the bottom. Replace rubber gasket.
6. Remove the three torx screws that hold the filter in place and change the filter making sure to replace the oring on the top of the filter.
7. Re-install the pan and the filler tube and fill the transmission with fluid.
8. It takes approximately 3 quarts on a filter change. Dexron ii or Mercon.
9. In the future I would change the transmission fluid at every oil change since it only changes 50% of the fluid in it.

Thanks to Bill Rickard

Procedure with no dip stick. (from Gary)
Changing transmission filter & fluid on transmission with no dip stick.
Jack up car and put on jack stands at all four corners, keeping car as level as possible. Remove aft drain plug from pan and drain fluid, reinstall plug.
Remove pan, remove & replace filter. Clean pan and reinstall with new gasket & new bolts ( bolts are self locking, one time use ). Now comes the fun part.
The new fluid needs to be between 86 and 131 degrees F. I put my quart bottles in the kitchen sink and filled it with hot water while I changed the filter.
I purchased a small plastic pump & 1 gallon gas can at Auto Zone along with 5 quarts of Dexron III.
Remove the fill plug on the side of the transmission, fill the gas can with the warm fluid and slip in the pump, ( it comes with a long plastic hose ).
Start the car and put the transmission in neutral.
Slip the plastic hose into the fill hole and start pumping in the fluid.
When the fluid starts coming out of the fill hole stop and reinstall the plug.
That's it your done. It sounds a lot worse than it really is, although a little time consuming.

Thanks to Bill Rickard

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