Anyone who’s ever driven through muddy terrain or encountered a patch of loose gravel on the road can attest to the importance of reliable tire traction. The necessity of dependable traction can become an even greater issue when factoring in a commercial vehicle carrying heavy loads, and the hard-working driver behind the wheel. In any vehicle, the differential works to transmit engine power to the wheels and enable stable turns, and specific types of differentials work in different ways to help prevent traction loss. A limited-slip differential (LSD) works to provide added power or grip to a wheel that has traction, while reducing the power to a slipping wheel.
While open and locking differentials have their own benefits, limited-slip differentials are an ideal choice for handling road conditions that could cause the wheels to slip. Wheels spin independently with an open diff, and a locking diff keeps both wheels spinning at the same rate; an LSD combines both concepts, dividing torque equally between the wheels under clear road conditions, and locking when there is a slip event.
In addition to better traction on paved surfaces and off-road, a limited-slip differential can contribute to less wear and tear on parts. During a turn, an LSD places less stress and pressure on the axle shafts since they can rotate at different speeds. That decreased stress can promote longer part life. A limited-slip diff can also prevent unnecessary wear on the tires by creating a better power distribution between the wheels with traction and the wheels that are losing traction.
For drivers of commercial vehicles, limited-slip differentials can help reduce the frustration caused by frequent incidents of poor traction and by a sense of instability during turns. An LSD that requires no driver input to engage can further support driver satisfaction and productivity. To recognize all these benefits, Dana Aftermarket offers the Spicer® Trac-Lok™ limited-slip differential for medium-duty truck drive axle applications.
The Trac-Lok acts as an open differential in normal operating mode, yet in a slip event it sends approximately three times more torque to the high traction wheel-end—without requiring the driver to engage any switches or mechanisms. It then returns to full differentiation as conditions change. At all times, the smooth, automatic operation is transparent to the driver.
The device supports efficiency in terms of both improved driver productivity and time in the shop. It is retrofittable with existing Spicer S110, S111, S130, and S140 axles with no wiring, sensors, air hoses, or pneumatic connections. To operate, it does not require switches, special lubricants, or friction modifiers.
Even with all the benefits provided by LSDs, there are certainly instances in which a driver may demand full power to both drive wheels. For the most severe applications, Dana offers the option of a locking differential* for S140 axles, which delivers full-locking, maximum traction. This diff option drives the vehicle even if one of the wheels is off the ground.
If you are looking for excellent handling on ice, snow, mud and dirt, a secure feeling on turns, and enhanced driver satisfaction, you may consider an upgrade to limited-slip differentials in your commercial vehicles. Backed by Dana, the global leader in driveline technology, Spicer Trac-Lok medium-duty differentials deliver these benefits within a lightweight, compact design.
For more information on this or any other Spicer driveline product, visit SpicerParts.com.
*Available with an Eaton® NoSPIN® locking differential. Eaton and NoSPIN are trademarks of Eaton Corporation.