The TeraFlex JK Front Locking Hub Conversion Kit serves to upgrade JK Dana 30 and 44 axles. This product brings a number of major benefits over the factory unit bearing design; it has the ability to dramatically reduce bearing load through the increase of distance between inner and outer wheel bearings inside the hub. The bearings rest on forged 4140 chromoly spindles that accept readily available, low cost industry standard seals and bearings. Through the incorporation of an 8 on 6.5" wheel bolt pattern, the design is able to use one-ton Dana 60 application components. This unique TeraFlex hub design allows the OE wheel speed sensors to be sealed from mud damage, as well as mud and other components. This helps ensure clear, constant date transmission for maintenance of all ESP and ABS functions. The Slimlock Hub kit comes with forged 4340 chromoly 35 pline stub shafts. This design also incorporates high surface area engagement for extreme durability. It is the perfect kit for flat towing, allowing hubs to be set in an unlocked position for transport. This Locking Hub Conversion comes with the TeraFlex dual piston Big Brake Kit. Remember that the 2007-2012 Dana 30 axles require new inner shafts to accommodate the larger u-joing end forgings. These are #303118 for driver side and #303134 for passenger side. All 2013 or older Dana 30 & Dana 44 JK axles will use the same U-joint.