Im actually a fan of the A442 and transmission rebuilding companies either say they are great or a clunky old box and don’t want to touch them (if you’ve increased the power). Many years ago their were stories of Viper engines being run in front of these with great success. Lockup kits were all the rage, but as torque levels increased, companies started getting scared about them slipping since the contact area on a standard torque converter isn’t that great.
Lots of companies offer upgrades to the A442F, and behind the FTE these can result in a very clunky low load 1-2 or 2-3 gear change and can only be nice when pushing them a bit harder. Lots have issues with slipping clutches and therefore off to a rebuild.
What do we know.
We were happy to do some testing on our cable line pressure operated A442F (previously behind a petrol and then behind an upgraded FTE. We didn’t actually have any work done to the valve body so shift changes were slow and at full power it would slip on the changes, but could hold when in gear. We did learn enough to know what makes a difference and is a worthwhile upgrade.
Except for the very first of the 1990 80 series Landcruiser A442F (which was fully hydraulic) the gear changes are controlled by an ECU when in D. The cable was used only for controlling internal line pressure.
The A442F behind the 1HDFTE and 2UZ, has an extra solenoid inside the gearbox specific for controlling line pressure and have no cable. This is because these engines have a fly by wire throttle, and I wouldn’t consider this to be an “upgrade” to the transmission, but rather a compromise as its application isn’t clever or have a great range.
Line pressure in the FTE and 2UZ can be increased for high load situations by putting a switch in the wire from the controller to the transmission. Effectively if the wire is cut you get max line pressure. This is because the spring that holds the pin down in the solenoid isn’t great and weakens with time so that for a set hold signal it will sit further off its seat and line pressure continues to drip with time. Also a modified valve body doesn’t seem to increase the rate at which the pressures ramp up but rather raise the whole pressures so you get that harsh low load gear change and nothing particularly impressive for line pressure.
SO…..What to do???
Based on what we have seen so far I would plan to install a valve body from a model with the cable controlled line pressure and use this in conjunction with a new boost controlled pressure device (soon to be released PDI LPC). Additionally we should organise the valve body upgrade (or do an exchange) since we have another fancy trick to get much more line pressure when under load.
The gear changes will continue to be done by the factory or an aftermarket controller, we just have our own control for line pressure and we have this based on boost pressure since on a turbo vehicle the torque comes from boost. This new system will give max line pressure above 20psi and 60-80psi when not making boost. This results in
the gearbox having very good strength when pushing it hard and being able to hold regardless of pedal position or how the tune and boost responsiveness is setup
at low load the shifts will be silky smooth as the line pressure is lower.
people doing FTE conversions into an auto 80 or 105 can keep the transmission, and these mods done while have line pressure controlled relative to boost.
Next Step.
If you are interested, please contact us via email to see if exchange valve bodies are available and then standby until the LPC product is released. We suggest not getting any valve body mods done until you see what we can do. If you don’t have a cable operated line pressure valve body then start hunting for one.
Is that the best we can do?
If you are pushing the A442F hard and considering a rebuild, I would install the Wholesale Automatic Billet torque converter and think about the extra clutch plate in the back end. Find a local place to do the main part (clutches etc) build, but due to complexity of automatic transmissions I don’t have a problem having experts in their field do each part. Quite a number of transmission shops know very little about torque converters and get them done by a specialist. Equally lots will offer to do your valve body, but we’ve been in lots of complete builds that aren’t ideal due to valve body setup.
NO - the 6R80 conversion is the best result for getting a strong smooth changing transmission behind your 6 cylinder and we expect to have these as a kit some time in 2022.