By now, just about everyone who's into four-wheeling has heard of lockers. Many people may not understand how they work, but they know how useful a locker or two can be on a tough trail. We have used every locker currently available and have been writing about them for years. We've tested different lockers in everything from a V-8-powered flatfender to a grossly underpowered fullsize GM truck. Here's the locker lowdown.
Automatic lockers will never let a tire spin slower than the ring gear. However, they will let a tire spin faster. This becomes necessary when cornering. The outside tire (axleshaft) of the vehicle needs to travel farther than the inside tire. To accommodate this the locker will release it, letting it spin faster and in some lockers also causing a ratchet noise. But once the speed of the two tires is equal again, or if it receives torque input (more throttle), the locker will lock both axleshafts to the ring gear once more. This can cause strange handling in corners, especially on lightweight, high-horsepower vehicles. Different designs have been used to try to limit the amount of squirrelyness and noise, and some lockers give you the option of having them on or off (selectable). But which locker is the best?