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Locker Lowdown

Front Under View
John Cappa | Writer
Posted August 1, 1998
Photographers: 4WOR Archives

By now, just about everyone who's into four-wheeling has heard of lockers. Many people may not understand how they work...

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  • Many consider the Tractech E-Z Locker and Powertraxx Lock-Right to be affordable and easy to install but can’t find many other good qualities. Some popping noises reminded us that the E-Z Locker was in the rear of this GMC, but the locker worked fine off road.

  • Dual Air Lockers were chosen for this Bronco to provide full control of engagement and disengagement, and to avoid abnormal driving characteristics on the street. One irritating factor we’ve experienced with all four ARBs we’ve tested in the past two years is the small air leaks that cycle the air compressor on and off while the lockers are engaged.

  • Here’s another supposed no-no: a Lock-Right in a heavy, fullsize truck. The locker had the typical on-road popping around corners but never let us down off road. We believe that many of the failures of these lockers are caused by excessive throttle at the wrong moment.

  • Detroit Lockers in both ends have long been considered the strongest setup, and we agree. You don’t have to think about them, and you’ll have to work pretty hard to break one.

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?


Chicago, IL 60609
Reider Racing
ARB 4x4 Accessories
Tractech (Detroit Locker)
Warren, MI
Eaton, Torque Control Products
Southfield, MI
Spectre Off Road
Chatsworth, CA