Controlling the Toyota A442 Transmission with the COMPUSHIFT

History of the Toyota A442 Transmission

The A442, designed and built by Aisin Warner, is an automatic transmission that was primarily made for the 80 and 100 series Toyota Land Cruisers.

It was released in 1990 as the successor to the A440 transmission, and was produced up until late 2002, before being replaced by the 5 speed A750 transmission.

As a heavy-duty transmission, it has proven to be a capable and dependable transmission in most of the vehicles it was released in. There were a few known issues with some models, but with simple fixes and upgrades they were resolvable.

Specifications of the Toyota A442

The A442 remained quite similar in design over its production. It is an automatic overdrive transmission with a lock-up torque converter clutch. It went from being a fully hydraulic transmission when first released, to becoming a completely electronically controlled transmission in its final version.

The first hydraulic A442 came out in 1990, and at first it only came behind diesel engines. From August 1992 onwards it was released for both the diesel and petrol 1FZ engine. The 2nd generation A442 came mostly computerized, meaning that the transmission had shift solenoids and both accumulator and lock-up solenoids. Although this 2nd version was electronic with solenoids it still ran a pressure control cable.

An easy way to identify the later August 1992 onwards version was by way of an added overdrive cancel switch on the gear select lever (gear shifter). The previous hydraulic version had no shift solenoids and was controlled by a mechanical governor with a throttle pressure cable.

From 1998 onwards, the A442’s operation became fully computerized. The throttle-valve cable was replaced by a pressure-controlled solenoid. This full electronic version continued to be in production until late 2002, and was only found behind the turbo diesel 1HD-FTE engine and the petrol 2UZ-FE V8 engine.

In terms of capability, all models are strong transmissions and similar in terms of torque capacity. The A442 can easily handle more than 228 hp and 430 Nm of torque produced by factory Toyota engines.

Any power mods such as adding a turbo can easily exceed the capability of the A442 in stock form. However, with the right upgrades the A442 can handle over 615 hp and 500 Nm of torque.

Gear Ratios of the A442F LandCruiser Transmission

1st 2nd 3rd OD R
2.950:1 1.530:1 1.00:1 0.765:1 2.678

Strengths of A442 Transmission

The A442 has proven to be a long-lasting and reliable transmission. Many Land Cruisers from the 1990s that came with this transmission are still running today, many hundreds of thousands of miles later.

One of the advantages of the A442 is its torque converter clutch (TCC). When the TCC is locked up, it provides a direct drive from the engine. It is typically locked at cruising speeds and this leads to less slipping and energy wasted in the torque converter.

The lock-up TCC along with the overdrive gear, which drops engine revolutions around 24%, leads to even more fuel savings and less engine wear over time due to the reduced rpm.

The fully electronic and final model of the A442 is by far the best in terms of transmission controllability and drivability. Based on the information from various sensors, the solenoids in the valve body can regulate the line pressure, leading to smoother shifting and an improved shift response.

Weaknesses of A442 Transmission

While most A442 transmissions have proven to be very reliable, there are a few known issues that have commonly popped up, mainly with the torque converter.

The torque converter in the diesel A442 is known to fail at times. The failure is usually due to a design fault, but can also come about as a result of excessive heat from towing excessive weights for long distances and from power upgrades. All of these factors tend to wear out and reduce the torque converter’s lifespan.

Replacing the Torrington bearing and using other higher quality components, as done in the Billet torque converter solved almost all of these diesel torque converter issues. The A442 torque converter that came attached to petrol engines luckily didn’t have the same issues and it was far more efficient than the diesel one.

Flaring between shifts is another issue that affects some A442 transmissions. It can be noticed by a sharp rise in RPM in the middle of shifts. This happens when the previous gear gets disengaged, but the following gear’s clutches don't engage on time.

In the hydraulic version, in the case of a 2-3 upshift flare, this was often the result of a loose throttle valve cable.

In the case where significant transmission upgrade is required due to a high power engine adding an extra clutch friction plate and removing every second piston return spring on the direct (3rd reverse gear clutch) will help greatly. It is also possible to add an extra friction into the intermediate (2nd clutch) but in both this and the above case machining of the apply piston will be required to make extra room.

Upgrading to a known performance valve body, such as a  Nomad valve body, will greatly increase the transmission's capabilities in all variants of the A442 transmission.

Custom Vehicles which use the A442 Transmission

The A442F in Land Cruisers can be modified to suit various engine upgrades and conversions such as turbo and supercharger upgrades or V8 and large displacement engine conversions. In all cases the A442F transmission is more than capable of handling these upgrades when it is paired with a COMPUSHIFT standalone transmission controller and valve body / transmission upgrades as previously discussed.


An 80 series Land Cruiser. The first vehicle the A442 was built for.

 
A 100 series Land Cruiser which featured the late electronic A442 transmission.

Controlling the A442 Transmission with the COMPUSHIFT

The COMPUSHIFT Sport transmission controller can be used to control the partially and fully electronically controlled A442 transmissions. Other than the very first A442 transmission which is fully hydraulic, the second and third generation can be controlled to different extents with the COMPUSHIFT Sport.

Based on throttle position, vehicle speed and transmission input and output speed sensors, the COMPUSHIFT Sport can be programmed to unlock and lock the TCC when appropriate. When accelerating heavily for instance, it can unlock the TCC to increase torque temporarily, and lock it up again when it makes sense to provide a direct drive from the engine.

The COMPUSHIFT Sport is the ideal controller to use when using an aftermarket engine control unit. It has a CAN-BUS interface allowing it to communicate with the engine and can modify the shift control as appropriate.

No expert knowledge of transmissions is needed with the COMPUSHIFT, because it comes with preloaded settings for a variety of different engines. The COMPUSHIFT Sport also has Bluetooth connectivity, allowing you to analyze and modify the transmission’s shift strategy on the go using a smartphone and the accompanying app.

To set up the A442 transmission to work with your vehicle, you will have to get the right kit and sensors according to your vehicle’s specifications. To find out what you need for your build, head on over to our  configurator tool to create your custom kit today. 

To get pricing for the COMPUSHIFT transmission controller click the below link to complete a quick questionnaire:

Transmission Controller for the A442