Yukon positraction internals for GM 12 bolt car and truck with 30 spline axles. Yukon positraction internals (0.806" diameter) for GM 12P and 12T with 30 spline axles. Yukon uses higher quality materials and better techniques than OEM to ensure a longer lasting spider gear set. This kit does not include clutches. All components come with a one year warranty against manufacturing defects.