What are lockers on a Jeep? This is one of the common questions that many people, perhaps even you, have because they are the secret to Jeep Wranglers’ excellent off-road capability. If your Jeep uses an open differential, everything will be running okay until it gets stuck in the mud, loose sand, or rocky tracks because only one wheel will be spinning. To overcome these off-road driving challenges, some Jeeps come equipped with differential lockers, but how well do you understand them?
Lockers help improve your vehicle’s 4-wheel power and traction. Join me as I dig deeper into the world of Jeep lockers to answer the main question, “Whatare lockers on a Jeep?” I will also answer common questions about the lockers and tell you some of the best models.
What Are Lockers on a Jeep?
A locker on a Jeep is a mechanical device used to lock the vehicle’s axle to ensure that power gets dispersed through the transfer case evenly between the wheels. The lockers can be fitted on the rear or front axles and help get strain off the vehicle when trying to overcome obstacles or challenging terrain.
To help understand this, it is important to know the different types of differentials and their benefits. Most vehicles designed with 4-wheel drive systems come with an open differential system, mainly as a stock option. The reason for this is that the open differential allows each wheel to spin differently. So, if you are turning a corner, the wheel on the outer end spins more than the inner one to avoid skidding.
The open differential will also come in handy in giving you traction most of the time. This differential also helps to prevent premature wearing of tires, and like most people, I find it awesome for street driving. The challenge comes when you get stuck, such as in a ditch or on snow, because only one wheel will be spinning. There are two options to remedy this, a limited-slip differential or a locker differential.
If your Jeep comes with a limited-slip differential, it combines open and locked differentials. In most cases, it will operate as an open differential but sends more torque to the wheel with greater traction. As you can see, the limited-slip differential is a great improvement to the open differential model. However, it is pretty complex and expensive. A good example of a limited-slip differential is the Yukon Gear & Axle Jeep JL & JT Dana 44 / M220 Rear Trac-Lok Limited Slip Differential.
The last model, which has become near sensational in the motoring world, is the locker differential. As the name indicates, the differential is made to “lock” both wheels together, allowing them to spin at the same speed. Without a lock differential, it would be very challenging, perhaps near impossible, to do any rock crawling because of different traction.
What Are the Main Types of Lockers in a Jeep?
Locker installations come in two main categories: the mini-spool model that fits in the ring gear and a full spool that replaces the entire ring gear’s housing. On top of these, the lockers used on Jeeps can be classified into several types.
The simplest model only keeps the differential locked all the time. However, this is not practical because you do not need the lock for on-road driving. Therefore, you should consider the other two models: the automatic lockers and selectable lockers.
If you select the automatic locker, it is pretty easy to install on your Jeep. The lockers activate automatically and stay locked when you accelerate. However, it also means that you can easily hop when accelerating around corners. This problem can be pretty challenging, resulting in control issues, especially for people who drive in slippery areas regularly.
The second option is the selectable model, which allows the driver to choose when to engage the lock. When disengaged, the selectable lock acts as a standard open differential. Then, you can engage it when driving off-road for better traction and vehicle control. The most important thing is to remember to disengage during on-road driving. Again, the installation of a selectable locker is more complicated compared to the open-differential model.
Does My Jeep Wrangler Have Lockers Installed?
Although some types of Jeep Wranglers are sold with selectable lockers, not all of them do, even when they are 4-wheel drive. If you want a jeep that comes with already installed selectable lockers, go for Rubicon. Also, you need to appreciate that some models might have custom-built lockers. If you already have a Jeep, here is how to determine whether it has a locker:
If you go under the car and check the differential (call it the pumpkin), you will notice a tube coming out of it. This is referred to as a vent tube. If there is a second line running out of it, chances are that it has a selectable locker.
To establish if the Jeep has an automatic locker, you will need to get inside the differential and have a look because they do not require a cable. So, are you ready to open the differential? We recommend this only if you have a background in vehicle mechanics or engineering. The better method is having a mechanic check it for you or driving to a Jeep dealership for enquiries.
Do I Really Need a Locker in My Jeep?
This is the main question that many Jeep owners or aspiring buyers ask. The answer depends on what you want in a jeep. A locker comes in handy if you get stuck or want to rescue a friend who is stuck. It will also come in handy when driving in sandy areas where equal traction on both the Jeep wheels is needed.
Sure, it is possible to rescue yourself without a lock when stuck, especially when the situation is not dire. However, extreme off-road driving, such as rock crawling, will be impossible without differential lockers.
When driving on mud or snow, a jeep without a differential locker is likely to feel like a 2-powered drive. Unless you only want to use your Jeep on paved city roads, a locker will be a great addition.
Front Locker or Rear Diff Locker: Which Is the Better Option?
As we have highlighted, lockers are crucial enhancements for off-road and extreme driving. Using differential lockers means that you can safely drive further off-road and safer than what standard diffs would allow.
If you only want to install one locker, where should it be installed? Should you chuck it on the rear or front?
To answer this question, you need to understand how a vehicle’s load and traction are re-distributed on rough/uneven terrain. So, let us get down to the basics of friction. To get friction generated by wheels, you multiply the friction coefficient by force. The force is the car’s weight, which is distributed evenly when the car is resting on an even surface. So, for a car moving uphill or carrying a load, the weight is re-distributed to the rear and vice versa when driving downhill. This means that positioning the lock on either rear or front has the same effect, but you need to introduce another parameter here—the position of the CV joint.
Because the CV joint, which is used for articulation and steering, is positioned on the front, it will not be a good idea to put the locker there. Although cases of broken CV joints are rare, it is not uncommon to hear reports of diff locked front ends ripping the CVs faster than usual.
The rear diff is the better option because the axles are free from the complexities of vehicle navigation mechanisms. Besides, a rear-axle locker can be turned on and off easily without overstraining the vehicle’s drivetrain.
Even when you opt to install the selectable lockers on both front and rear axles, it will be a great idea to only use the front one when doing extreme off-road driving. Then, disengage it as immediately as possible for on-road driving.
What are lockers on a jeep? When going off-road and into very challenging terrain, be they slippery areas or rocky hills outdoors, a diff locker is very useful and might be the only way out. This post has demonstrated that lockers fall into several categories, and you should go for the best model for your Jeep.
The selectable locker stood out from the pack because it allows you to engage it only when driving off-road and operates as a standard open differential locker for on-road driving. Remember to ensure the differential lockers and the entire transmission system, including the engine, the gearbox, and the cooling system of your Jeep, are always in top condition for better performance.