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TJM's New Pro Locker

Posted in How To on August 1, 2011
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There is a new locking differential hitting the States right now, and OFF-ROAD magazine was one of the first to receive TJM’s new Pro Locker—a locking differential that goes from an “open” position to a completely “locked” position using an air-driven actuator. But this isn’t what you think it is. Yes, coincidentally TJM is also an Australian 4x4 products company, but this is a mechanical locker activated by an air-and-spring-operated actuator that uses a fork to push or pull an internal selector ring on the differential, mechanically engaging the lock ring and subsequently locking both axleshafts together.

Upon initial inspection, we were impressed by the thick carrier and liked the optional compressor package that came with the Pro Locker. The air compressor, solenoids, wiring, and air lines were all there, and we liked that a hard reinforced rubber air line is supplied to connect to the bulkhead on the axlehousing. From the bulkhead, a copper air line routes down to the air-and-spring-operated actuator. This is where we got a bit excited. Though the Pro Locker works fine out of the box, we started geeking out on the potential for needless modification of the actuator, and for some great trail fixes should the actuator ever lose air pressure somehow.

For now, we’re taking an initial inspection of the newest locker to hit the USA. We installed the Pro Locker in a rear Dana 44 axle using a West Coast Differentials 4.10:1 ring-and-pinion set and WCD full installation kit with Timken bearings. We’ll have a long-term update in an upcoming issue of OFF-ROAD after we get some time and abuse…er, use, on it. OR

Differential Type: Locking differential with open and locked positions
Locking Actuation: Mechanically locking with air-driven actuator
Application tried: Standard Dana 44
Axle Spline Count: 30
Carrier Split: 3.73:1 and (numerically) lower / 3.92:1 and (numerically) higher
Ring Gear Size: 8.5 inches
Estimated Cost: $800

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West Coast Differentials
Rancho Cordova, CA 95742

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