Propickup Digital Magazine
Issue link: http://read.dmtmag.com/i/150744
ARB Auburn Gear Eaton Performance OX Locker Richmond Gear arbusa.com auburngear.com eatonperformance.com ox-usa.com richmondgear.com LOCKERS & LIMITED SLIPS SOURCES LIMITEDSLIP DIFFERENTIALS BUYERS GUIDE AUBURN LIMITED SLIP Auburn offers two versions of its LSD, including a Pro Series that has a more aggressive torque bias. Heavier trucks should certainly consider the Pro Series. The Auburn LSD is a coneclutch design and requires a friction modifier additive in the lubricant. Cone-clutch LSDs are not rebuildable because the cones are specifically matched to the case; however, cone LSDs generally last longer than clutch types. Also, Auburn has a D-REX program so owners with units less than four years old can trade in for a new Auburn LSD for the about the same cost to rebuild a comparable clutch-type LSD. Street price: $325 to $650 for the standard LSD and $400 to $550 for the Pro Series. EATON TRUETRAC When the going gets tough, these factory axle options/upgrades make driving through easier wheel and transfer power to the wheel with greater traction. Clutch-type LSDs will wear out and need to be serviced or replaced. Currently there is only one gear-type LSD in the aftermarket, so availability may be a problem. Most truck owners seeking a traction upgrade prefer a locker. There are two types: automatic and selectable. The automatic locker distributes torque equally to both wheels at all time by literally locking the axes together. When going through a turn, the locker "unlocks" and allows the outside wheel to rotate faster than the inside wheel. The unit then locks again when torque is applied. Automatic lockers are strong but also noisy, may increase tire wear and may deliver a harsh ride on the street. These aftermarket automatic lockers are not to be confused with the factory automatic lockers that normally run with an open differential then automatically engage the locked mode when sensing wheelspin. The selectable locker allows the driver to move between an open differential for normal use and a fully locked axle for offroading or inclement weather. Depending on the model of locker, the driver operates the locker electrically, pneumatically or with a hand cable. Selectable lockers are the most expensive and installation is more complex. But the driver has full control over the locking function, so street performance is unaffected while in the unlocked mode. Adding an aftermarket LSD or locker shouldn't interfere with the factory traction controls, but problems can always surface with A quiet and smooth-operating LSD, the Truetrac utilizes a helical gear design and is pretty much maintenance free and doesn't require a friction-modifier in the lubricant. It's built with forged gears under tight tolerances for a strong mesh. The design is fully automatic. Long-time enthusiasts may remember this differential under the Tractech brand, which was purchased by Eaton about six years ago. The Truetrac is often a strong choice for a front differential due to its negligible impact on steering and tough reputation, but experts may warn against using tires over 33 inches tall. Street price: $375 to $750 EATON POSI The Eaton Posi hasn't changed in design but materials and tolerances are much improved since the unit was first introduced in the '50s. The Posi uses carbon-disc clutch packs that are preloaded by a central spring assembly and located behind each differential side gear. One of the Posi's benefits is that it can be "tuned," depending on the spring strength and the preload. The Posi can also be rebuilt after the clutches wear out. While the Posi isn't the most effective traction-control option, it's affordable and has built one of the most loyal followings of any automotive brand. For those truck owners with an open rear differential seeking additional traction for a tow rig or those worried about inclement weather, the Posi merits strong consideration. Street price: $475 to $800 warranty issues if the claim can be traced to improper installation or design flaws. Also, some aftermarket dif- ferentials are extremely strong and may strip the axle splines if bigger tires are installed on the truck. propickupmag.com PROPICKUP 75 ProPickup_2013BB_Lockers Limited Slips.indd 75 8/6/13 10:18 AM