4WD Automatic Transmission Upgrades

External Automatic Transmission Coolers

Overheating is the number one cause of 4×4 automatic transmission failure in Australia. Very few vehicles have satisfactory OE automatic transmission cooling systems, particularly when the vehicle use involves 4WD touring with towing.

Virtually all OEM systems rely on feeding the automatic transmission fluid through a heat exchanger coil/cooler that is mounted either inside the bottom radiator tank (vast majority like this), or onto the side of the transmission itself (ie Ranger PX range)

You can understand that these systems don’t assist greatly when the vehicle is under stress, either due to higher transmission temperatures or higher engine temperatures. These stress times are when towing reasonable to heavy loads, highway running in hot weather, beach driving or even desert crossings, really any slow heavy 4×4 work situations.

There is no such thing as too much transmission cooling. A well cooled transmission increases the life and performance of your transmission.

An external cooler, external to the engine cooling system, assuming the cooler is of the appropriate size for the vehicle, is a far more efficient system.

Our External Automatic Transmission Coolers generous are generous in capacity, and come in a rugged kit built for off-roading.

You could continue to run the transmission oil through the bottom of the radiator, but we recommend you bypass that and go direct to the new front mounted cooler.

For 2 reasons, the radiator heat exchanger/coil corrodes, allowing transmission into the coolant – result is all the rubber components in the engine go soft.

Plus coolant can flow into the automatic transmission – result is total transmission failure leading to an expensive rebuild.

Also, better cooling, the transmission temperature is independent of the engine temperature.

An external cooler, external to the engine cooling system, assuming the cooler is of the appropriate size for the vehicle, is a far more efficient system.

Our External Automatic Transmission Coolers generous are generous in capacity, and come in a rugged kit built for off-roading.

You could continue to run the transmission oil through the bottom of the radiator, but we recommend you bypass that and go direct to the new front mounted cooler.

For 2 reasons, the radiator heat exchanger/coil corrodes, allowing transmission into the coolant – result is all the rubber components in the engine go soft.

Plus coolant can flow into the automatic transmission – result is total transmission failure leading to an expensive rebuild.

Also, better cooling, the transmission temperature is independent of the engine temperature.

Summary

• Australian manufactured
  
• High flow all aluminium cooler
  
• Heavy Duty purpose built mounting brackets
  
• 4mm thick anti-vibration and anti-twist
  
• High quality anti corrosive coated brackets
  
• Comprehensive DIY Kit inc Large cooler, hosing, clamps, hardware
  
• Comprehensive DIY Instructions
  
• Experienced Technicians available for fitting
  
• 3 Year Unlimited Km Warranty
  

Torque Converter Lock Up Switch

To stop the up-down hunting of the 4WD automatic transmission when towing, to increase fuel economy – particularly when towing, to extend transmission life – by reducing transmission temperatures, to dramatically improve downhill engine braking – by locking the engine to the transmission output – these are all the symptoms that can be rectified by fitting a Torque Converter Lock Up Switch.

How does it work?
The torque converter is a device that sits between the engine and the automatic transmission. It’s referred to as a fluid coupling, with an unlocked or free spinning mode and a locked or engaged mode. The transmission computer (TCU: Transmission Control Unit) automatically controls when the torque converter is switched between these two modes. It is speed and load dependent.

When your vehicle is travelling in a situation where the TCU calculates that the torque converter lockup can be applied, a solenoid is activated sending oil pressure to act on a clutch inside the torque converter, which in turn ‘Locks’ the engine output shaft (crankshaft) and transmission input shafts together – so they spin at the same speed. (Like releasing the clutch on a manual gearbox)

The primarily reason is to reduce heat build up and also reduce fuel consumption.

For ‘normal’ driving, city or country, with little load, this system works well.

However, when the vehicle is towing and/or in off-road conditions, it can be quite frustrating as the factory TCU appears confused and is constantly changing the state of the torque converter clutch. In-Out, In-Out, constantly hunting! Very annoying and not conducive to long transmission life.

With the assistance of the Torque Converter Lockup Control System, the driver can override the factory torque converter lockup circuit providing a relaxed and enjoyable driving environment. This is done via the torque Converter Lock up Switch.

The operation of the Torque Converter Lockup system is designed not to impact the vehicle’s standard operations in any way. It has been specifically designed so that when the switch is OFF, the torque converter circuit is operating under the factory TCU, with no modification to the circuit.

When you activate the Torque Converter Lockup switch, the system takes control of the torque converter clutch circuit. It provides the factory ECU with a signal that mimics the solenoid and prevents any diagnostic warning lights illuminating on the dashboard.

Upgraded Automatic Valve Bodies

What is a “Valve Body”?
Automatic transmissions have a valve body that controls the shift mechanism, controls the pressures on the clutch plates and the direction of the gears.

It is like a maze with lots and lots of valves. The valves can be controlled via hydraulics or via electronics (in late model vehicles). Each of the valves either prevents oil from flowing, allows it to start flowing or varies the pressure at which it can flow. When a valve is opened the oil can apply pressure to a clutch or route the oil to another valve. By combining a series of valve opens/closes, the transmission can engage or disengage certain clutches which in turn can shift gears, engage the torque converter lockup, or neutralise. So one set of valves might give you 1st gear, while another set of valves might engage reverse.

By re-calibrating the flow of this oil through the use of modified valves, separating plates and springs, we can affect how clutches apply, provide better lubrication, increase longevity and even increase the flow to standard or external coolers.

There are 3 versions or level of valve body upgrade available

• Nomad Valve Body
  
• Extreme Valve Body
  
• Full Manual Valve Body
  

The Heavy Duty Nomad Valve Body Upgrade is perfect for Towing and Touring where you are looking for improved fuel economy, improved shift quality and a more enjoyable driving experience. It’s also ideal for those who have added a performance chip or remap and exhaust system gaining you around 30% improved engine performance.

This is by far our most popular valve body upgrade.

Summary

• Improved the shift quality to a more crisp positive shift pattern
  
• Reduced the flaring or slippage on gear change
  
• Improved downhill braking
  
• Reduces transmission temperature
  
• Reduces fuel consumption
  
• Extends auto transmission life
  
• Designed and manufactured in Australia to suit the harshest conditions
  

The Heavy Duty Extreme Valve Body Upgrade is designed vehicles with significant power increases. Oversize turbos, high flow injectors, superchargers, and any other aftermarket engine modification to gain more power. The shifts are going to be quite firm but that’s the compromise with large power gains.

The Heavy Duty Full Manual Valve Body Upgrade is for comp truck style vehicles. Designed for competition style driving. 2 throttle positions – On and Off. Removes all automatic shifting and in some cases requires you to activate the overdrive gear and torque converter lockup via seperate switches.

This valve body is definitely not designed for daily driving.

If you would like any further information or to discuss any automatic transmission upgrades, please make contact with one of our experienced staff.