OS Giken BMW E87 135i (MT Only) / E92 335i (AT Only) Super Lock LSD

The OS Giken SuperLock LSD (BM531-HA) is a high-performance limited-slip differential designed for the BMW E92 135i and 335i with the N54 engine. It features a patented pressure ring design and a spline-through-side-gear system that accommodates up to twice as many friction plates as competing designs, ensuring smooth, progressive locking and 100% lock capability with low preload, resulting in quiet operation and predictable performance. Constructed for exceptional durability, the unit utilizes chemically heat-treated, high-grade steel alloy components, raw-forged gears, and precision-machined clutch disks. The LSD case is machined from a single billet piece for uniformity and strength. This LSD is designed for 215LW 3-bolt type differentials found in early 135i (MT) and 335i (Large Type Case Only). It may require custom removal and machining for later generation 215LW Spline Type differentials.