Blackline Traction Systems Helical LSD features equal rotational speed to both wheels with torque distributed according to traction. With minimal service requirements - no clutches or special gear oil required. The Blackline Helical LSD benefits from quick reaction compared to viscous LSDs and has gentle and progressive engagement with low noise levels. The Blackline Helical LSD is easily controllable for power take-off and drifting. It's gears and body are manufactured from 8620 alloy steel and are designed to be a direct replacement into stock differential / axle.