When it comes to taking your Jeep off road, there’s a lot of talk about the type of differential you have. The reason is simple: there are three different types, and each serves a different purpose. There are also a few different types of locking differentials as well, and you’ll want to choose carefully depending on the type of driving you do most frequently.
The three types of differentials are open, limited slip, and lockers. The stock differential on your Jeep is open unless you opted for the optional limited slip. Locking differentials are aftermarket and are for those who are really serious about their off-road adventures.
Most vehicles with selectable four-wheel drive have an open differential, at least as a stock option. The reason? This type of differential lets each rear wheel spin at a different speed. This means when you’re turning corners, the rear end does not hop or skid.
An open differential prevents premature tire wear and helps you keep traction in many situations. This is best for on the street and even handling snow, but only when both wheels have equal amounts of traction. The issue comes in when you get stuck because only one wheel will be spinning while the other one simply does nothing.
A limited slip differential combines the best of both a locked and an open differential. It acts like an open differential in most conditions, but when you’re stuck, it sends more torque to the wheel that has the most traction. While these are better than open differentials, they’re more mechanically complicated, so they cost more to replace.
A locker or spool is designed to do just what it says. It locks both wheels together so they spin at the same time with an equal amount of torque. This is why a vehicle with a locker will “hop” when it turns. The outside wheel has further to travel, so if it can’t freely roll, it will bounce as the other wheel forces it around. However, if you’re going straight up a hill or crawling over rocks, a locker is exactly what you need.
There are two types of locker installations. One is a full spool that replaces the entire housing for the ring gear, and there’s a mini-spool that fits inside the existing ring gear. Either way, the effect is the same.
In addition, there are a few types of lockers. The first simply keeps the differential locked at all times. This is the simplest type, but it’s not practical for on-road driving and is really only good for extreme off-road activities or drag racing. There are two options for those who want the advantage of a locker off road but also want to be able to use their Jeep on the street.
The first is an automatic locker. The installation of these lockers is quick and easy, but they do have some drawbacks. While they’re always ready when you need them, they also stay locked as long as you’re accelerating. This means when you accelerate around corners, they can lose traction or hop, causing handling issues. This is especially true if you live where there’s a lot of snow.
The second is a selectable locker. This is a good choice for a number of reasons. The first is you can choose when it is engaged and when it’s not. When disengaged, it acts like an open differential. The key is that you need to remember to disengage it on the street or it can cause some serious driveline damage to your Jeep. Installation is more complicated and these differentials are more expensive, but they can give you the best of both worlds.
This is the biggest question, and for many Jeep owners, the answer is no. When you’ll need a locker most is when you get stuck (self-rescue) or someone else is stuck (rescue). The other time they’re most useful is when you’re doing rock crawling or are four-wheeling in sandy areas where equal traction to both wheels is essential.
Can you rescue or self-rescue without a locker? Sure, in many cases you can, depending on how badly you’re stuck. However, rock crawling and extreme off-roading are different stories. Without lockers, slippery rocks or sand can turn your four-wheel drive into a two-wheel drive, or sometimes a one wheel drive. If all four wheels aren’t on the ground, or a rock is covered with slippery dirt, being without a locker can be a serious problem.
At the same time, snow and mud also make for similar conditions, and a locker can mean the difference between driving away and being stuck and doing some walking, digging or jacking.
When you get off the road and into some rough stuff, a locker becomes really desirable and even a necessity. Automatic and selectable lockers are best for most people who also drive their Jeeps on road, but if you’re lucky enough to have a dedicated four-wheel machine, a full-time locker might work for you.
It’s up to you to do your research and decide if you need a locker at all, and which one is right for you.
TireBuyer carries an impressive stock of tires for your Jeep, plus we offer fast and free shipping. You can easily shop by size or year online or call our tire and wheel experts at 866-961-8668.