Yukon Powr-Lok Race positraction for Dana Spicer 50 with 30 spline axles. Will chatter. The Powr-Lok is one of the most aggressive and strongest limited slips ever designed. It uses a two-piece case and six forged internal gears for added strength. The Powr-Lok uses a ramping-clutch design to become more aggressive as tire-spin increases. The composite clutches provide long life and high performance. All units are Rebuildable and come with a one year warranty against manufacturing defects. Inner axles must be shortened a minimum of 1/4 inch per side for proper fit. For Twin Traction Beam front applications, part number Detroit 4610 must be ordered as well.