Lock-Up Kits – FAQ

Common Questions for Lock-Up Kits

Why do I need a Lock-Up Kit?

  • Significantly reduce fuel consumption while towing on the open road – you will get an extra 2L to 6L per 100km.
  • Gain 100% engine braking for difficult descents (just like a manual) on road and off road, perfect for towing on-road or when tackling those low range steep hills.

Note that 100% engine braking via 1st gear lock-up is available on some stock transmissions. However, all transmissions running our Nomad Heavy Duty Valve Body can activate lock-up in first gear.

How does the Lock-Up Kit work?

The torque converter is a device that sits between the engine and the automatic transmission. It is referred to as a fluid coupling with an unlocked or free spinning mode and a locked or engaged mode. The transmission ECU automatically controls when the torque converter is switched between these two modes. When your vehicle is travelling in a situation where the ECU calculates that the torque converter lock-up 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 and transmission input shafts together so they spin at the same speed. This primarily is to reduce heat build up and also reduce fuel consumption.

Due to most vehicles being manufactured and tested to be operated on sealed roads in suburbia, the torque converter clutch usually works perfectly. However when the vehicle is in towing and/or offroad conditions, it can quite often cause frustrations to the driver as the factory ECU appears confused and is constantly changing the state of the torque converter clutch. With the assistance of the GENII Torque Converter Lock-Up Control System, the driver can override the torque converter lock-up circuit providing a relaxed and enjoyable driving environment.

Why didn’t the manufacturer put a Lock-Up Kit in the car in the first place straight from the factory?

The manufacturer of these vehicles are required to build to a worldwide market, unlike the Australian way of life where we tow excessive weights and multiple upgrades including larger offroad tyres. Other countries will simply not even fit a tow bar or consider a single upgrade. This leave the manufacturer having to build a vehicle to suit a very wide market. Obviously the manufacturer has to come up with an average to suit both ends of the spectrum as best as possible, however with the availability of upgrades to suit the Australian way of life allows us to build products such as the lock-up kit specifically for the Australia way of life including their excessive weights and multiple upgrades including larger offroad tyres. This changes how the car drives and increases the benefit you get from a torque converter lock-up kit. By locking the engine output shaft and transmission input shafts together so they spin at the same speed reduces heat build up and also reduces fuel consumption.

  • Reduces sluggish, slow gear changes on both up and down shifts including kick down.
  • Improves engine responsiveness.
  • Upgrades the transmission’s natural ability to provide engine braking by 10-15%.
  • Improves fuel economy.
  • Decreases transmission temperature.


What happens when the valve body goes bad?

Driving with a faulty transmission valve body is something that impacts on driving ability and can create problems when changing gears. Some symptoms of a bad transmission valve body include:

  • Hearing banging or knocking noises when pressure is applied to the brakes
  • The car slows down when the car is put in reverse mode or driving backwards
  • The transmission has problems when downshifting
  • Problems when changing gears to reverse or drive
  • The car’s transmission may get stuck in neutral

How much does a valve body cost?

A quality value body from Wholesale Automatics will cost between $1,295 and $1,595 depending on the make of vehicle. This is a premium valve body with many advantages as listed under “Why do I need a valve body?”

Can a bad valve body be repaired?

Depending on the nature of the damage to the valve body it may be possible to rebuild and repair the valve body instead of replacing it entirely. This may be a cheaper option.


If you want more details on Lock-Up Kits not found on these pages then please contact our team as we are more than happy to help.

Contact us to arrange your Lock-Up Kit Now!