How to Change the Transmission Fluid in a LeSabre

Updated July 20, 2017

The transmission in your Buick LeSabre is designed for smooth and comfortable shifting. The transmission in the Buick needs regular maintenance like all the other components on your Buick. Changing the fluid needs to be done every 40,000 miles to ensure the fluid is fresh and free of debris. Always change your filter out when changing the fluid. The filter protects the fluid and can get to clogged to pull debris and sediments out of your transmission fluid. Dirty Transmission fluid can cause potential transmission problems in the future.

Locate the drain plug at the bottom of the transmission. Unscrew the drain pan with a crescent wrench. Ensure there is a pan underneath to catch the fluid.

Tighten the plug back to the pan when done draining. Slide drain pan out from underneath the car.

Loosen the twenty bolts around the transmission drain pan with a socket wrench. They will be scattered around the pan.

Lower the pan from the bottom of the transmission. The pan may be stuck to the bottom of the transmission. You can tap the pan with a hammer to loosen it. The gasket will seal the pan to the bottom of the transmission.

Clean the pan by scraping the gasket material off the edges with a putty knife or razor blade. Spray and wipe out the inside of the pan with brake cleaner. Wipe out with a fresh towel.

Unscrew the transmission filter from the bottom of the transmission with a socket wrench. Place filter with the old transmission fluid.

Attach new transmission filter with socket wrench. Ensure it is installed tight in the transmission.

Spread new gasket around the drain pan. Ensure all the holes on the gasket line up to the bolt holes on the pan.

Bolt the pan to the bottom of the transmission. Start threading all the bolts to the transmission but do not tighten until they are all started. Tighten the bolts with the socket wrench.

Open the bonnet to access the transmission level dipstick. This will be a yellow round handle located to the back of the motor.

Place a funnel in the dipstick tube of the transmission. Pour in six quarts of transmission fluid labelled "Dexron 3". This is the appropriate fluid for this vehicle.

Clean the dipstick off with a clean towel and insert in to the dipstick tube. Pull the tube out and check the level of the fluid. Where the fluid stops on the dipstick, the level will be indicated next to it. Add additional fluid of required in half quart intervals. The system holds 6.5 quarts of fluid.

Start the car and allow to run for five minutes. This will warm up the vehicle. Shift the car through all the gears and back to park. Turn off vehicle.

Check fluid level and add if level is not at the full mark on the dipstick.


The transmission filter part number for the Buick is GM 8651909. Consult owner's manual or contact dealer to verify this is accurate.


Contact your recycling centre for disposal of old fluid and dirty filter. Use extreme caution when working around transmission fluid as it is a toxic chemical.

Things You'll Need

  • Crescent wrench
  • Drain pan
  • Socket set
  • Socket wrench
  • Transmission filter
  • Transmission pan gasket
  • Razor blade
  • Putty knife
  • 7 quarts of Dexron 3 transmission fluid
  • Clean towel
  • Funnel
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About the Author

Gregory Crews has been in the film industry for three years and has appeared in more than 38 major motion pictures and 16 television shows. He also writes detailed automotive tutorials. His expertise in the automotive industry has given him the skills to write detailed technical instructional articles.