I wonder how many countless middle schoolers have been subjected to the inhumane pre-teen ritual of being stuffed into a cramped school locker? While I have never personally experienced it myself, I’m sure that the mere mention of the word “locker” to anyone who has been, is enough to cause one to instantly forget their locker combination and quite possibly to lose partial control of their bodily functions. How on earth are you supposed to remember if you go counter-clockwise past ‘32’ twice before stopping on ‘17’ when you’re in constant and profound fear of becoming the defenseless victim of a wedgie; or, worse yet, having your lockers interior exposed to those who don’t share your same fondness for fuzzy animated movie characters or cheesy boy bands?
Fortunately, the word ‘lockers’ has an entirely different and less-emotional connotation to the off-road Jeep enthusiast. “Lockers” is short slang for a locking differential- the means by which the men are separated from the boys when the tires hit the trail.
Most vehicles, including many Jeeps, leave the factory with an “open” style differential. What this means is that the rotation of the driveshaft is transferred through a set of gears and distributed to two separate axle shafts, each turning its own driven wheel. Since the two axle shafts are not actually connected together through any rigid means, they are able to rotate at different speeds independent of each other. While this concept is splendid for driving on the open road and around town, it loses its luster in off-road situations where one wheel may lose traction and will begin to spin wildly. The other wheel, despite having sufficient traction, might just sit there and do nothing while all of the engines torque is applied to the wheel with no traction. It’s very much like watching an innocent and unknowing bird fly headlong into a glass window again and again. After several minutes, there has been lots of motion, vast amounts of spent energy but no real progress. This is a condition that off-road enthusiasts commonly refer to as “stuck”.
“Lockers”, or locking differentials, essentially drive both wheels with constant and equal torque, regardless of traction, making it much more difficult to achieve the status of stuck, as is common in an open differential-equipped rig. While the perceived invincibility found in driving off road with lockers is quite attractive, it can also be accompanied by a whole new set of drawbacks. Applying unrelenting torque to a tire that is hopelessly wedged up in a rock pile will eventually find a way to turn itself loose despite the tires resistance. This newfound and forced freedom is brought on by the sudden failure of whatever component lacked the most in the integrity department. If you’re lucky, it’s just a u-joint. More than likely , such a calamity will befall a more expensive component. And one that is significantly harder to repair on trail side, like an axle shaft or, heavens forbid, a costly CV driveshaft. Even at such high cost, Lockers ARE the way to go if you like to wheel off-road.
Those who are blessed with the ability to be free-thinkers may instinctively suggest that we just build ALL Jeeps, or cars for that matter, with locking differentials and send those open differentials down the road, the way of the Dodo bird and full-service gas stations. After all, nobody really wants to get stuck, do they? Certainly not any number of my personal friends who I can recall having gotten their Jeeps stuck in their own back yard while doing something as simple as hauling furniture or flexing their macho manly side by attempting to persuade a shrub from its earthen nest by brute force. Nothing is quite as masculine as winching your Jeep out of a muddy pit that used to be your yard while using a kid’s swing set as an anchor point.
The bottom line is that all of the traction benefits offered by a locked differential are overshadowed by their negative on-road manners. Since very few roadways are completely 100% straight, the need to turn the steering wheel occasionally is very real and turns the prospect of locked differentials into a nightmarish ordeal; similar to the horrors of getting stuck in your own yard. Since the opposing wheels are essentially “locked” together inside the differential, going around a corner becomes a nerve-grinding experience.
When you steer a vehicle through a corner, the wheel positioned on the inside of the turn has a shorter distance to travel while the outside wheel has a longer distance to negotiate. This conflict in rotational energy between the inside and outside wheel manifests itself in a vehicle that simply isn’t happy turning at speed anymore; never mind the larger diameter tires and pavement-hating tread. In fact, a lot of this excess energy in the turns will be absorbed into your driveline and by your tires tread, resulting in reduced fuel economy, accelerated tire wear and a downright poor overall attitude. Three things that Jeeps can’t afford to compromise on unless there are substantial benefits to be gained. Benefits like x-ray vision or George Clooney-like good looks would be good contenders.
Any time the left is so far removed from the right, it’s good to know that an accord can be struck and a happy middle ground established. Ground where we can enjoy the off-road benefits of locking differentials combined with the street-friendly mannerisms of an open differential. Such an accord can be found in a selectable locker, a differential whose locking abilities can be turned off or on with the simple flick of a switch, the pull of a lever or by reciting a short mystical chant. Such systems would include an ARB Air Locker, Eaton E-Locker or a cable-actuated OX Locker.
While the selectable locker is a bit more expensive that most other options, it’s hard to identify any negatives to support an argument that they are anything but worth the price you’ll pay. Jeep has utilized a selectable locker system in their Rubicon models since the early 2000’s and it has quickly become a consumer favorite for its expanded level of capability. So much so that you’ll find Rubicon stickers plastered across the hoods of Cherokees, YJ Wranglers, and even an occasional Grand Cherokee. While obviously the decal doesn’t make any Jeep a Rubicon, what does make the Rubicon stand out can be largely attributed to its locking differentials, front and rear. Just try to comprise a similar locking differential system in a base model Wrangler and you will concede that the Rubicon package is a smart way to go. Trust me… a lot can be said for being able to drive out of your own back yard and it’s hard to put a price on shame. OlllllllO