YUKON GRIZZLY LOCKER, Dana 44 JK 30Spline. The Yukon Grizzly Locker is a mechanical locking differential. It features a forged case and 8620 internals for maximum strength. It’s patent pending design reduces common locker failures. All units assembled in the USA!Everything about the Yukon Grizzly Locker is hardcore, its casing and gears, its advanced gear tooth design, and its impact on traction and performance. The Yukon Grizzly Locker is a mechanical positive-locking differential thats engineered for rock crawling, serious trail running, off-road racing, and drag racing. The unit provides 100% power to both tires, while still allowing for disengagement while negotiating turns. The Yukon Grizzly Locker is a patented design that features innovations that make it tougher than the competition. Its inner clutch teeth have a larger radius at the base, which offers up to 350% greater strength versus back-cut designs. The Grizzly Lockers larger teeth also resist breakage caused by shock-loading or catastrophic axle failure. Its a serious piece of mechanical engineering for serious driving conditions.Fits Jeep JK non-Rubicon rearPatented internal design reduces common locker failures8620 internals for added strengthAssembled in the USAFits:Jeep Wrangler JK 2 Door (2007-2018)Jeep Wrangler JK 4 Door Unlimited (2007-2018)