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What Are Lockers on a Jeep? What You Need to Know!

The Jeep is one of the most iconic cars on the market. It has an 81-year-long history and continues to handle many challenging situations as it first did on the battlefields. In addition, many still dream of ownership because of its excellent design and build quality, and a big part of the allure is its off-road capability from its locker system.

A locking differential is essential for a car to keep good traction on all wheels when handling uneven, loose, or slippery terrain. In an open differential, when a vehicle comes to a slippery surface where both wheels experience different amounts of traction, they tend to send power to the wheels spinning the most. Or the one with the least traction, keeping the vehicle stuck in a slippery situation.

However, Jeeps combat this with a locker by locking the wheel with the least traction and sending power to the one with the most. In turn, this keeps a vehicle moving and enables it to put power to the ground at all times. If you’d like to learn more about Jeep differentials and lockers, keep reading.

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What is a Differential or Locker?

A differential, also known as a locker, is a mechanical apparatus that allows for the rotation of wheels connected by the same axel at different speeds. It also allows for independent rotation of wheels, even though they are on a single axle. This means that when a vehicle loses traction on one wheel, the wheel can spin freely until it grips the driving surface.

On the other hand, Jeeps also need a differential to improve handling and cornering performance. This is because when a vehicle is going through a bend or trying to make a turn, the inner wheel has less ground to cover than the outside one. If the two wheels are only on one axel and both travel at the same speed, the vehicle’s handling will not be good because both want to spin at different rates.

However, with a differential, both wheels can spin independently, maximizing traction and turning ability.

When a Jeep loses traction and some wheels start to slip, a differential utilizes pressure plates in the axel to limit power to said wheels. The locker prioritizes more drive power to the wheels with more grip, enabling a Jeep to crawl out of sticky situations where other vehicles can’t.

differential lock for off road vehicle
Image Credit: TinoFotografie, Shutterstock

Different Types of Lockers

1. Open Differential

Open differentials are the most common type of differential found in vehicles. They improve the car’s handling by allowing wheels to turn at different speeds around corners. However, an open differential is unsuitable for off-roading as it prioritizes power to the wheel with the least traction.

To see if your Jeep has an open differential, lift it on some jacks and then spin one wheel. If the other spins in the opposite direction, your Jeep has an open diff. You should probably avoid hitting trails with it.

2. Spool

A spool is when your Jeep lacks lockers and both opposite wheels are connected by a single shaft. They lack autonomy and move in synchrony no matter the driving conditions.

A Jeep with a spool can perform well while off-road driving but compromises its handling for reasons we have already highlighted. However, if you plan to crawl your Jeep up a few rocks in the park or make it oversteer in certain bends, then a spool will do you great.

3. Automatic Differentials

An automatic differential switches automatically between a spool and an open differential depending on the driving condition. It operates as an open differential during normal driving conditions and as a spool when the driving gets sticky, ensuring your Jeep performs optimally in any situation you throw at it.

However, it would be best if you did not put all your trust in this system as sometimes it can have a mind of its own and not perform as expected. So if your Jeep’s locker is automatic and you plan on taking it to the trails, have a backup plan just in case you get stuck and the locker does not cooperate.

a lifted jeep on the mountains
Image Credit: ElyPenner, Pixabay

4. Lunchbox Locker

If your Jeep has an open differential, and you want to take it trailing while on a budget, a lunchbox locker will work for you.

It works by changing the spider gears in a regular open differential with locking ones. It works great and still keeps stellar driving performance on the road as well as improves the off-road capability of a Jeep with an open differential.

However, it raises the noise profile of your Jeep, especially when going through turns. But with the cost savings and added performance, most still find the conversion worth it.

5. Limited Slip Differential

A limited-slip differential is another type that gives you the best of both worlds. It acts as an open differential in normal driving conditions and as a spool when your Jeep goes off-roading or encounters some challenging situations. But unlike a spool, it does not fully lock the wheels and allows them to rotate at different speeds.

This Jeep locker allows for the prioritization of the wheel with the most traction but keeps the other wheel spinning, but at a lower velocity—making it different from a spool.

One thing to note about this differential is that the size of the tire affects its performance.

6. Selectable Lockers

Selectable lockers work using an airlock system to add pressure when opening and locking. They need a 12v battery and an air tank or compressor to work. However, they are highly nimble and work well in most situations.

wrangler jeep in the forest
Image Credit: Piqsels

What Are Jeep Lockers Used for?

Jeep lockers are mostly helpful in off-road situations where you have to go through mud or rough and hilly terrain. Or, if you’re feeling courageous enough, crawling up rocks. In such situations, it’s not uncommon for a wheel to lift off the ground and get suspended in the air. A locker will assist you in keeping traction in the wheels that are still on the ground and keep you moving.

In addition, if you’re likely to encounter a lot of surfaces with different traction levels, a locker will help you put the power down. For example, an asphalt driveway that has snow on one side. A locker would enable your Jeep to deliver power to the wheels with the most traction and keep you moving instead of getting stranded.

Another situation where a locker is essential is when you’re pulling something—let’s say another friend’s Jeep with no differential that’s stuck in a ditch. A differential would help your Jeep keep the most traction on all four wheels and make pulling easier.

However, most Jeeps come with only an open differential as their standard locker, except for the Jeep Wrangler Rubicon. For better off-road performance, you would have to modify or install a locker that would enable you to unleash the full potential of your Jeep.

Advantages of Jeep Lockers

  • Cornering and control: Because wheels can independently slow or speed up while going through turns, a Jeep’s handling is significantly improved. You can confidently take corners, knowing your back wheels will not slip out on you or react weirdly to cornering forces.
  • Increased efficiency: Differentials increase a Jeep’s traction and reduce power wastage from spinning wheels that are not working. Maximizing traction on the road also increases speed and efficiency, which is why differentials are popular with high-performance cars.
  • Safety: Differentials prevent your Jeep from unknowingly oversteering, which is extremely dangerous when in traffic or at high speed. Furthermore, they improve your Jeep’s handling, which makes driving safer.
  • Variability: Differentials can lock and unlock to fit different driving conditions. To maximize the driving experience, you can change how the differential reacts to give you the best performance.
Black Jeep Wrangler
Image Credit: Kenny Eliason, Unsplash

Can you Add Lockers to Your Jeep?

You can absolutely add lockers to your Jeep! It mostly applies to SUVs because of their off-road capability, however, Jeep’s heritage in the off-roading scene makes it more special to have a locking differential.

Conversions take just a few tools, simple OEM parts, and some mechanical know-how. But if you’re not mechanically adept, you can always take it to your trusted mechanic to do the conversion for you. Furthermore, depending on the conversion you’re looking for, it can be as simple as welding your part to your axel or adding a few parts for more functionality.

car and road divider

Conclusion

Jeeps are beloved by many for their capabilities both on and off-road. However, they come in all shapes and sizes and have different technology depending on when they were made. As a Jeep owner, you sometimes want to hit the trails and still be comfortable driving to work. A good locker on your Jeep allows you to do that.


Featured Image Credit: cody lannom, Unsplash

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