How to Fill a Torque Converter

by Richard Rowe

Torque converters (a.k.a. "stall converters") are a type of fluid coupler that transfers power from the engine to the transmission. Torque converters transfer power by using an engine-mounted turbine to push oil (fluid) through a transmission-side turbine until that turbine can no longer pass fluid without moving. Unfortunately, many torque converters can only be refilled while the transmission is already out of the vehicle. However, you can refill some if they are equipped with either a lock-up torque converter or torque converter drain plug without removing them from the vehicle.

Refill the Converter

1

Stand facing the torque converter.

2

Grasp the torque converter firmly with both hands and pull it toward you with only a slight amount of pressure.

3

Turn the torque converter counter-clockwise until you hear a sharp click and it moves toward you about an eighth of an inch.

4

Turn the torque converter counterclockwise until it slides off of the transmission input shaft.

5

Set it on a flat surface with the large hole in the converter hub facing upward.

6

Slowly fill the converter with the amount of fluid specified for your car. This can be anywhere from three to ten quarts. Don't worry about overfilling it; any excess will flow into the transmission.

7

Lift the torque converter and quickly slide it back onto the transmission input shaft to minimize spillage.

8

Turn the converter clockwise while pushing slightly. You will hear a sharp click denoting that it's in the first channel.

9

Continue turning counter clockwise till you hear another click and then give it another two turns.

Tips

  • check If your converter has a drain valve, then you can refill it in the car. Assuming it's completely drained, rotate the torque converter until the valve is as horizontal as you can get it. Connect a two foot length of 3/8ths inch plastic tubing to a large plastic syringe and fill the syringe with fluid. Slide the tube's end into the drain hole, start injecting it with fluid until you hit about four quarts and put the valve screw back in.
  • check If you've got a car with a separate plug for the torque converter lock-up control, you can run a jumper wire to the converter lock-up terminals to lock the engine and transmission together. When you start the engine, the now-locked converter will turn the transmission's oil pump, allowing you to fill the converter simply by adding transmission fluid through the fill tube.

Warnings

  • close Make sure the converter is completely seated before you re-install; it's easy to make a mistake here and destroy your entire transmission. Give the converter a tug to see if it slips off without turning.
  • close If you have the option of a locked-converter re-fill, you'd do well to have a mechanically inclined friend over to help you. If you pull the wrong plug you can easily wind up sending voltage through the wrong circuit. Back-feeding some circuits can fry the transmission's computer, so consider this an expert tip for experienced mechanics.

Items you will need

About the Author

Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.