How to Change Automatic Transmission Fluid and Filter on 1966 Mustang

You jump in your car and notice that is feels like it is slipping out of gear or shifting in and out of neutral. What could the problem be? One problem may be that the transmission fluid and filter need to be changed.

In this tutorial, you will learn the steps to do this yourself. We are changing the fluid and filter on a 1966 Mustang. Other automatic transmissions are similar, but may vary on make and model on car.

Watch Video

Raise Car

Jack car or place on lift. If using a jack, use jack stands to secure car. Never craw under a car with only a jack holding it up.

Counts Transmission Pan Bolts

Count the number of bolts holding the transmission pan on. Give parts store the motor you have and the number of bolts holding the pan on. 11, 15, or 17. This will give them the information to get you the right filter and gasket.

Transmission Fluid

Buy 4 to 5 quarts of Type F transmission fluid.

Place Drain Pan Under Car

Place drain pan under transmission pan. (Wearing gloves will keep you much cleaner.)

Drain Fluid

Loosen one side of transmission pan to allow fluid to drain.

Remove Transmission Pan

Remove all 11 bolts and remove holding pan and remove pan.

Remove Transmission Filter

Remove 1 7/16 inch and 8 5/16 inch bolts holding filter in and remove filter.

Remove Gasket

Remove gasket. This may require a gasket scraper.

Inspect Transmission Pan

Inspect pan for any highs. Hammer and dolly highs level if you find any.

Install New Transmission Filter

Install filter using a cross or star pattern.

Install Transmission Pan

Place grease on flange of transmission pan to hold gasket in place. Then Install transmission pan using a cross or star pattern. (12-16 ft. lbs)

Lower Car

Remove drain pan and lower car off of jack stands.

Add Transmission Fluid

Add 4 quarts of Type F transmission fluid.

Start Your Engine

Start engine and allow idling to warm up. Check for leaks then re-check dip stick. If low add more transmission fluid.

You Will Need:

1. Watch The Video
2. ½ inch Socket, Ratchet, and Extension
3. 7/16 inch Socket
4. 5/16 inch Socket
5. Replacement Filter
6. Replacement Transmission Pan Gasket
7. 4 to 5 Quarts Type F Transmission Fluid
8. Drain Pan
9. Gasket Scraper
10. Gloves