The Yukon mini spool for Ford 9-inch with 28-spline axles installs into an open carrier to replace spider gears and provides 100% torque to both wheels at all times. It’s a cost-effective traction device suited to off-road or dedicated racing setups; Yukon recommends full spools for vehicles with very large tires or high horsepower.
Yukon Gear Mini Spool For Ford 9in w/ 28 Spline Axles