Rear Trac Loc Carrier Case by Yukon Gear & Axle®. Without Spider Gears. Yukon Gear and Axle manufactures a full line of standard open and positraction carrier cases for a variety of applications. The castings and machining are kept to the highest of standards to produce a carrier which provides both high strength and tight tolerances for long life. Dominate the track or hit the trails with confidence by fine tuning your vehicle for neck-breaking speed and performance with this premium differential component that delivers the ultimate in high strength and toughness. This part is designed to provide the gearing that helps ensure your engine stays in the powerband for faster acceleration while providing maximum safety during tough driving conditions.