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Eaton Detroit Truetrac LSD - Helical-Gear Limited-Slips

Posted in How To on September 10, 2008
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Photographers: Courtesy Of The Eaton Corporation

All too often, we see guys jump quickly to put a locking differential into their truck's or 4x4's axle. Though this can be a great addition, there are some applications where a limited-slip differential (LSD) would work just as well, if not better. In fact, there are a couple of us at the magazine who prefer an LSD over a locker in certain vehicles.

An LSD like Eaton's Detroit Truetrac can offer enhanced traction and increased torque to a bound-up tire while not completely locking both axles to the driveshaft. It stays 100 percent street-friendly and adds increased control in slippery situations while remaining completely safe to drive with in icy road conditions. An LSD can keep a mostly stock axle from grenading when a locker would have broken an axleshaft or worse, and it still very much acts as a traction-aiding device.

The Detroit Truetrac was the first helical-gear-type limited-slip engineered with no wearing parts that need to be replaced. It's a fully automatic limited-slip that performs "open" until needed, but they do require some minor loading up (resistance) to perform properly.

We went to the folks at Currie Enterprises to watch them install a Truetrac into a third member for a Ford 9-inch axle. We've decided that this is the differential we want to run in our '93 Ford Bronco that sees a lot of highway and town driving to and from the dirt.

Having a limited-slip differential in the back of our Bronco is great. It helps a lot in sandy situations and is even noticeable on rocks when a tire starts to pick up during suspension flex. We got the chance to spend an entire week in the rocks, dirt, mud, and even snow in Moab, Utah, earlier this year with an LSD. Our Bronco performed excellently in all the conditions and was a blast to drive.

- Traction - aiding device
- Helical - gear- type limited- slip has no parts that wear out
- Can prevent drivetrain breakage where a locker would grenade other components
- Open - differential operation until traction is compromised
- Can be used in front differentials without inhibiting steering characteristics
- No need to run LSD additives

- Does not transmit 100 percent drive force to both axles
- Priced higher than some lockers

PhotosView Slideshow


Currie Enterprises
Corona, CA 92880
Cleveland, OH 44114

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