What Does a Diff Lock Do? – A Detailed Explanation

Written by

Charles Bolte


Vernon Hoppe 

what does a diff lock do

Vehicles like 4x4s are equipped with differentials, which allows the engine’s generated power to traverse towards the differential. The power is then spread out to your vehicle’s wheels.

There are times that you would need to activate it by pressing the Diff Lock button. So what does a Diff Lock do?

The diff lock allows you to go through extreme off-road conditions and sticky obstacles by literally locking the differentials, as the name suggests, meaning that equal power is spread out to the wheels so that they can rotate at the same pace when traction is needed.

What is a Diff Lock?


Diff lock meaning is differential lock, referring to a kind of modification that works as a locker that is equipped with the differential shaft usually found in the middle of the vehicle’s wheel axles, and it consists of cogs or gears.

You can identify it by looking for the Diff Lock Symbol on your dashboard, which is a small logo of the four wheels of your vehicle with an “X” mark or sometimes the word lock in the middle.

In some cases, the symbol contains a padlock with the four wheels drawing. Some car models allow you to lock the front and rear axles and they are represented with the word “Front” or “Rear” with a padlock symbol in it.

What Does a Differential Lock Do?

As mentioned earlier, the diff lock helps your vehicle move forward by giving equal traction to both wheels in off-road and difficult terrain.

  • When the diff lock is engaged, it locks the wheels and axle so the wheel with the more resistance receives half the power as that of the other wheel which has less resistance.

For example, let’s say that one of your front wheels gets stuck in a deep and rocky obstacle and starts to spin, then the other wheel which is gripped perfectly on the ground and has more resistance will not get power from the differential.

Therefore the solution for this is to use a locking differential on a truck when in off-road situations like this wherein the diff lock will give power to the other wheel which is stationary on the ground. This will give it a “boost” and the traction will allow both wheels to move forward.

How Does a Differential Lock Work?


There are two types of diff lockers that will allow you to engage it during extreme road conditions, namely the automatic and the manual diff lock.

1. Automatic Diff Lockers

The automatic diff locker does not require the user’s intervention to activate it, and generally does all the work for you whether you are driving on-road or off-road as you steer your wheel.

As soon as the torque is applied, it automatically locks the wheels’ axles without the need for a switch to engage it. Essentially, they are easier to navigate when it comes to steering, particularly for front differentials.

2. Manual Diff Lockers

Contrary to the automatic diff locker, the diff lock can also work by means of manual methods. Usually, there is a switch or button used to engage it, located on the dashboard of your vehicle.

These manual diff lockers, also known as selectable lockers, require driver intervention. So it is better to assess the road or driving condition in order to know when to activate your diff lock.

These kinds of differential locks are beneficial, especially on a tractor, since tractors are used more on off-road locations like farming grounds. It is engaged by manually stepping on the differential lock pedal.

How to Use a Diff Lock?

We must keep in mind that a Diff Lock should only be used off-road which requires us to put in extra traction to drive our way through difficult terrain.

Engaging your Diff Lock while on the road with good traction can cause problems and may damage your car’s acceleration and steering system.

Frequently Asked Questions


The Importance of a Diff Lock

The Diff Lock helps your vehicle pass through off-road terrain to avoid damage to your wheel and to avoid your wheels spinning out in deep mud or gravel.

It allows the power source from the vehicle’s engine to be equally distributed to the wheel that is on the ground with more traction so it can function and move forward together with the wheel that is spinning and has less traction.

When Would You Use a Diff Lock?

Use diff lock only when you are driving on a surface that would need more traction such as slippery or icy roads, rutted hills, dirt, and mud.

It can also be activated when the vehicle is moving in low range, either first or second gear. It’s also possible to use the diff lock on the verge of losing traction on the wheels.

How Fast Can You Drive With a Locked Diff?

When the Diff Lock is engaged, it is advised not to exceed 25mph. Generally, fast driving can damage your vehicle and can cause accidents so it is best not to exceed 25mph while engaged in Diff Lock.

What is the RR Diff Lock?

Also known as the locking rear differential, it keeps both wheels from spinning on their own. By engaging this, your vehicle greatly reduces the chance of losing traction.

How to Activate Differential Lock in Snowrunner?

Differential locks in the Snowrunner simulation can be activated when you shift into low-gear mode. This puts the players’ skills to the test, as they navigate through different kinds of challenging off-road terrains.

Can You Use Diff Lock on 4×2?

4×2 vehicles are also capable of using the Diff Lock on rough terrains like sand, mud, or grounds covered in gravel. However, compared to a 4×4, the 4×2 has a lower range and limited momentum, as users tend to drive in the clutch which is more tedious.

The Difference between Center Diff Lock vs Rear Diff Lock

Center Diff Locks are often used in AWD and 4WD vehicles. The power and torque are divided to the front and rear wheels to give it balance, and to rotate at the same speed.

On the other hand, the Rear Diff Lock only keeps the rear wheels of your vehicle rotating at the same amount of speed.

Difference between Lock and Unlock Differential

Lock differentials secure the wheel and axle together so both wheels can receive traction on difficult terrain. While the unlock differential or open differential allows each wheel to spin independently.

It is not advised to use open differentials on off-roads since the engine’s power is distributed to the wheel with the less traction


Now that we have covered a wide array of topics and questions about diff locks, including its meaning and functions. You now know that it equally gives power to the front and rear wheels to help give more traction in off-road driving.

The Diff Lock gives you a worry-less driving experience through rough terrain and sticky road obstacles. We hope that this article about What Does a Diff Lock Do help cover your questions, especially about its functions and significance.

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