Let's Play Ball - September - 2021

Servicing the Cooling System in the AC60E

Now that summer is in full swing more and more transmissions are burning up in the hot summer sun. Giving the example of the northwestern heat of 120+ degrees reaching from Canada all the way down through into Mexico, it’s just plain hot! Keeping those transmissions cool is vital to the operation. In this example we’ll cover the Toyota AC60E from service to cooling. The AC60E transmission was introduced as a light to medium duty transmission.

The AC60E is a 6-speed, rear-wheel drive, electronic-controlled transmission. It consists of a converter, three planetary gear sets, five friction, one mechanical clutch assembly, and of course the electronically controlled solenoids and pressure system. It shares many characteristics and strategies with the A960, A760 and AB60 models. Architecture is similar between the variants, however, the AC60 is a far simpler design.

The AC60 is paired mostly with gas and diesel V6 applications. Isuzu uses it behind their 2.8L diesel engine in the D-Max model. The AC60F designates the four-wheel drive unit (Figure 1), and AC60E designates the two-wheel drive application (Figure 2).

The applications are as follows:


  • 2019-present – Land Cruiser V6
  • 2015-present – Tacoma 2.7L gas
  • 2015-present – Prado 150 Series
  • 2015-present – Fortuna GUN Series
  • 2015-present – Hilux 2.4L (gas and diesel)
  • 2019-present – Hiace 2.8L diesel
  • 2019-present – Commuter 2.8L diesel
  • 2015-present – Innova
  • 2015-present – Cresta
  • Isuzu
  • 2015-present – D-Max TF Series 2


There are a variety of cooling system configurations that may be present with this unit. The configuration will depend on the model and application. Although the transmission has cooler fittings that can be directly routed to a remote cooler, most models incorporate a cooler/warmer attached to the transmission housing (Figures 3 & 4). There is a special procedure when servicing a unit with the thermostatic bypass valve. Follow this procedure especially when you are servicing the auxiliary cooler and related cooler lines. First locate and identify if your vehicle is equipped with a Thermostatic Bypass Valve (Figure 5). If it does have a valve follow these steps for the transmission fill procedure after servicing:

  1. Locate the thermostatic bypass and use compressed air to blow the dust off of the thermostat cap to clean it.
  2. Using a screwdriver, push the shaft of the thermostat until the screwdriver contacts the step inside the cap.
  3. With the shaft of the thermostat pressed, push a pin (diameter: 1.0– 1.8 mm [0.039″–0.070″]) into the hole on the side of the thermostat cap. Slide the pin in until it passes through the hole on the other side of the thermostat cap to fix the shaft in place. This process disables the thermal bypass element (Figure 6).
  4. Fill the transmission (See Servicing and checking the transmission fluid level)
  5. Reinstall the refill plug to prevent the fluid from splashing.
  6. Remove the pin to enable the thermal bypass element.


There are two methods for servicing the transmission fluid for this unit. You can remove the drain plug only or you can remove the pan and do a full inspection with a filter replacement (Figure 7).

There are also two ways for checking the fluid level. One way requires the scan tool, the other does not. Whichever method is used, the temperature of the fluid when the level is checked is most critical. Either way fluid needs to come out of the level check plug at a certain temperature. It is recommended to use Toyota WS Fluid only.

The location of the fill plug on both the 2WD and 4WD applications is on the extension housing. Use a 15/16” socket to remove the plug (Figure 1 & 2). There is also an alternative fill location on the passenger’s side of the case near the output speed sensor (Figure 8). Always remember to check for the correct fluid level at the specified temperature range of 39° – 49°C (102 – 120°F).

NOTE: In the following example we are using the factory tool.


Checking The Fluid Level With The Techstream Factory Scan Tool

  1. Connect Techstream to the DLC3
  2. Turn the tester on and enter the following menus: “Powertrain / ECT / Data List”. Check A/T Oil Temperature 1.
  3. Allow the engine to idle until the fluid temperature reaches 39°C (102°F). The fluid temperature must be between 39° – 49°C (102° – 120°F) to accurately check the fluid level.
  4. Remove the overflow plug with the engine running and check and see if fluid comes out the overflow tube.
  5. If no fluid trickles out, add fluid until it begins to trickle out. Once fluid trickles out of the overflow plug the service is complete.


Checking The Fluid Level Without The Techstream (Using the D Shift Indicator)

CAUTION: During this process you’ll be jumping the DLC3 connector, be sure you have the correct pins before performing this procedure.

  1. Connect terminals 4 and 13 on the DLC3 using an SST (or equivalent jumper tool) (Figure 9).
  2. Move the selector shift lever back and forth between N and D every 1.5 seconds for at least 6 seconds and/or two cycles, until the D shift indicator comes on.
  3. When the D shift indicator on the combination meter comes on for 2 seconds, it indicates that the fluid temperature check mode has been activated and started.
  4. The shift indicator will come on again when the fluid temp reaches 46° C (115°F ) and will blink when exceeds 56° (133°F ). Always allow engine to come up to temperature of 115°F.
  5. Check Fluid Level. The fluid temperature must be between 39° – 49°C (102° – 120°F) to accurately check the fluid level.
  6. Remove the overflow plug with the engine running and check and see if fluid comes out the overflow tube. If no fluid trickles out, add fluid until it begins to trickle out.
  7. Install the overflow plug and remove the jumper tool.


  1. Install the overflow plug.
  2. Stop the engine.
  3. Remove the refill plug.
  4. Add ½ qt. of fluid.
  5. Allow the engine to idle and wait 10 seconds.
  6. Go back to Checking the fluid level above.
  7. After filling the transmission install the overflow plug with a new gasket and torque to 15 ft lbs.
  8. Stop the engine and install the refill plug with a new O ring and torque to 29 ft lbs.
  9. Install the case cover.

Even though these types of services are becoming longer to perform, its making sure you’re doing it right that keeps your customer coming back. And it’s the best way to beat the heat!