A Locker is a mechanical unit that is sensitive to torque application. It will lock (drive both wheels) under acceleration, or unlock (allow the axles to turn at different rates) during coast or deceleration. A very strong piece, since it doesn’t use any clutches or cones that can wear out, which made it a good choice for it’s original truck application. Since driver input mainly determines whether the unit is locked or not, it can be very frustrating to a driver who is unfamiliar with the operation of the differential. Hard acceleration during a turn will cause the unit to lock and skid the tire. Between lock and unlock, a distinctive “clunk” can be heard. During a properly executed turn, clicking will be audible since locking teeth are allowed to jump each other inside the unit. Learn More

Similar in the design as the open, but have a series of friction plates between the side gear and the case. Standard Duty units have them behind one side gear, Heavy Duty have them behind both. There is a spring or springs that apply tension between the case, clutch pack(s), and the side gears . By increasing friction in this way, it requires more load variation before the clutches release and allow the gears to start rotating and speed-up the outer wheel. The number of plates, their material, and spring pressure will alter the release point. The clutch packs can be replaced when worn-out, but their replacement cost might be prohibitive.Learn More

A helical gear differential is a mechanical unit that, unlike the Locker, offers smooth and progressive power transfer. If one tire begins to slip relative to the other tire, a separating force is created between the pinion gears and side gears. This generates internal friction which slows the spinning wheel and sends power to the wheel with the most traction. These differentials are comparable to the strength of a Locker, but without it’s downsides. The Strange 9” S-Trac, due to materials and design, exceed the strength limits of the Locker while offering all the benefits of a helical gear unit.Learn More

Strange Engineering 35 Spline Ford 8.8 Helical Differential w/Special Side Bearings, Races, and Shims

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