In its relaxed state, the OEM snap ring outside diameter is much greater than in its installed position, requiring increased deformation to permit assembly. This results in a ring that is highly stressed as installed. Each time the clutch applies, the ring must absorb the force. This compromises the structural integrity of the ring, often resulting in shattering. This high quality heat treated snap ring features an increased cross sectional area and will not fail under extreme loading conditions. A must on all TH400 builds.