How To Use Diff Lock The Right Way



A locking differential (diff lock) can give your vehicle the boost it needs when caught in tricky, off-road situations. Knowing how and when to employ the diff lock will enable you to traverse difficult terrains with ease, helping you get more from your off-road vehicle.

Read on to learn what differential lock is, why it’s important and how to use your locking diff when driving.

What is Diff Lock?

The four wheels on your 4X4 need to be able to run at different speeds, to enable your vehicle to turn corners efficiently. As such, all powered axles – front and rear in a 4WD - have a differential. This differential will direct power to the wheel that is easiest to rotate – providing different power to each wheel according to its needs.

Cars only have one differential, but 4X4 vehicles can have up to three differentials – front, centre, and rear.

A differential lock secures this differential in place, making all the wheels on the axle move at the same speed. This pushes equal power through to all wheels, which is needed when handling difficult terrain.

Why is Your Diff Lock So Important?

The diff lock forces all wheels to spin at the same speed, regardless of traction. This is helpful if you encounter difficult terrain and one or more wheels leave the ground, as full power remains on the other wheels ensuring you are still moving in the direction of travel.

For example, let’s say you are driving over rocky terrain and one of your wheels leaves the ground. This may be the wheel that has the most driving power, leaving the other three wheels struggling to get enough traction to push the vehicle forward. A locking differential ensures that maximum power is put into all wheels, providing a much-needed boost to your forward propulsion.

Therefore, your differential lock provides a traction control system and is a key component to preventing wheel spin, which can prove a life saver in treacherous driving conditions, such as snow or ice.

How to Use Your Diff Lock When Driving

First, a diff lock should not be engaged for on road driving, unless weather conditions such as snow or ice mean that extra traction is required. Use your locking differential when you want to go off road, for driving on difficult terrain, such as dirt, gravel, mud or snow. You will only need to engage your locking differential when you need extra traction, so you may only use it for a few moments on each off-road adventure.

There are two types of locking differentials – automatic and manual

Automatic diff locks will engage automatically when traction is lost. The diff lock will release once traction has been regained. Some automatic locking diffs will only disengage once one wheel is required to spin faster than the others.

Manual diff locks put the driver in control, enabling them to decide when and if extra traction is required. There are various types of manual diff locks, most of which are worked using a switch on the dashboard or gearstick. These either work with compressed air, an electromagnet or are cable operated.

When your differential is locked, your vehicle will want to drive in a straight line, making corners difficult. Listen to your vehicle and do not put undue stress on it, otherwise you could cause serious damage to the axles.

Off road enthusiasts differ on opinion as to which of the potential three diff locks (front, rear or central) works best, and while a rear locking differential seems to be favoured, you will find your own system as you take to the tracks.

Once you have mastered your differential lock, traversing off road will get a whole lot more exciting, as you will be able to take on more challenging tracks and difficult terrains.