BMW 215LW Fully-Forged LSD Unit – F-Series N55 & B58
Fully-Forged Limited Slip Differential (LSD) Unit for BMW 215LW — F-Series N55, B58 & High-Torque Models Transform the traction and handling of your BMW F-Series with the RacingDiffs Fully-Forged 215LW Limited Slip Differential (LSD) Unit. Designed as a high-performance LSD upgrade for BMW models equipped with the 215LW differential, this unit delivers strong, predictable locking, improved acceleration out of corners, and significantly better control under power. Developed for powerful rear-wheel-drive and xDrive BMW applications, the 215LW differential is commonly found in some of the most popular performance models of the F-Series generation, including the BMW M135i, M235i, 335i, 340i, 435i and 440i, as well as high-torque diesel models such as the 125d, 225d, 325d, 330d, 335d, 425d, 430d and 435d. Whether your BMW is powered by the legendary N55, the highly tunable B58, or one of BMW's high-torque N47, B47 or N57 diesel engines, the RacingDiffs Fully-Forged LSD unit is engineered to provide the traction, strength and adjustability required for performance street driving, track days, drifting, hill climb, rally and other motorsport applications. Features Fully forged construction: Both the LSD housing and internal components are forged for exceptional strength, durability and resistance to high torque and shock loads. Designed for BMW 215LW differentials: Purpose-built for the 215LW differential family used across a wide range of high-performance BMW F-Series models. Adjustable ramp settings: Three lock profiles allow the differential behavior to be tailored to your driving style and application: 30/30 — aggressive 2-way configuration for drifting and maximum locking response on acceleration and deceleration. 30/60 — versatile 1.5-way setup for hill climb, rally, circuit racing, time attack and performance driving. 50/65 — progressive and smooth engagement for performance street use and track days. Premium clutch pack: Equipped with 4 × molybdenum-ceramic clutch plates engineered for consistent locking performance and supplied with a Lifetime Warranty on the clutch plates. Strong mechanical preload: Provides immediate and predictable differential response without relying on electronic intervention to transfer torque between the driven wheels. Optimized NVH: Correct setup, preload and high-quality LSD oil provide smooth operation while maintaining strong locking performance. High-power ready: The fully forged architecture is designed for tuned N55 and B58 engines, high-torque diesel applications and demanding motorsport use. Performance Benefits Improved traction: Transfers torque more effectively between the driven wheels, reducing unwanted one-wheel spin and improving acceleration out of corners. Better power delivery: Helps powerful BMW N55 and B58 models put their torque to the ground more effectively. Enhanced corner exit: Allows earlier and more confident throttle application when accelerating out of a corner. Predictable handling: Mechanical locking provides consistent and repeatable differential behavior at the limit. Improved drift control: Strong and adjustable locking characteristics make the car easier to initiate, balance and control under power. Motorsport versatility: Adjustable ramp configurations allow the same LSD platform to be optimized for street, track, drift, hill climb, rally and time attack applications. Built for high torque: Forged construction is engineered to withstand the demanding torque output of tuned BMW N55, B58 and high-performance diesel engines. Technical Specs / Installation Tips Differential type BMW 215LW Construction Fully forged housing and internal components Ramp options 30/30 (2-way), 30/60 (1.5-way), 50/65 (smooth progressive lock) Default configuration 50/65° unless otherwise specified Clutch pack 4 × molybdenum-ceramic clutch plates Clutch plate warranty Lifetime Warranty Recommended applications Street, track, drift, hill climb, rally and time attack Oil recommendation High-quality 75W-140 LSD oil, such as Ravenol Racing 75W-140 or equivalent Backlash target 0.08–0.12 mm on most BMW ring-and-pinion sets Professional installation recommended: Correct carrier bearing preload, ring-and-pinion backlash and contact pattern should be checked during installation. Backlash setup: Always measure the original setup before disassembly and verify the final backlash and gear contact pattern after installation. Important: Differential compatibility should be confirmed by differential type rather than chassis or engine alone, as specifications may vary depending on production date, transmission and market. Compatible BMW Models — 215LW Differential Fitment This Fully-Forged LSD unit is designed for the BMW 215LW differential found in the following applications: BMW 1 Series F20: 125d N47S1, M135i N55 F20 LCI / Facelift: 125d B47, M135i N55 F21: 125d N47S1, M135i N55 F21 LCI / Facelift: 125d B47, M135i N55 BMW 2 Series F22: 225d N47S1, 225d B47, M235i N55 F23: 225d B47, M235i N55 BMW 3 Series F30: 325d N47S1, 330d N57N, 330d xDrive N57N, 335d xDrive N57Z, 335i N55, 335i xDrive N55 F30 LCI / Facelift: 325d N47S1, 325d B47, 330d N57N, 330d xDrive N57N, 335d xDrive N57Z, 340i B58, 340i xDrive B58 F31: 325d N47S1, 330d N57N, 330d xDrive N57N, 335d xDrive N57Z, 335i N55 F31 LCI / Facelift: 325d N47S1, 325d B47, 330d N57N, 330d xDrive N57N, 335d xDrive N57Z, 340i B58, 340i xDrive B58 F34: 325d N47S1, 330d N57N, 330d xDrive N57N, 335d xDrive N57Z, 335i N55 BMW 4 Series F32: 425d N47S1, 425d B47, 430d N57N, 430d xDrive N57N, 435d xDrive N57Z, 435i N55, 435i xDrive N55, 440i B58, 440i xDrive B58 F33: 425d N47S1, 425d B47, 430d N57N, 435d xDrive N57Z, 435i N55, 440i B58 F36: 425d B47, 430d N57N, 430d xDrive N57N, 435d xDrive N57Z, 435i N55, 440i B58 *BMW differential specifications may vary by production date, transmission, drivetrain and market. If your exact vehicle configuration is not listed or you are unsure whether your car uses a 215LW differential, please contact us before ordering. Why Upgrade Your BMW F-Series to a Limited Slip Differential? Power is only useful when it can be transferred effectively to the road. On powerful BMW F-Series models, especially tuned N55 and B58 cars, an open differential can limit traction by allowing one wheel to spin when accelerating hard or exiting a corner. A mechanical clutch-type Limited Slip Differential improves torque distribution between the driven wheels, helping the car accelerate more effectively and behave more predictably under power. The result is improved traction, stronger corner exits and greater driver control. For popular performance models such as the BMW M135i, M235i, 335i, 340i, 435i and 440i, a properly configured LSD is one of the most significant drivetrain upgrades available—particularly for modified, high-power, track or drift applications. The RacingDiffs Fully-Forged 215LW LSD combines the strength required for high-torque applications with adjustable ramp geometry, allowing the differential to be configured around the way the car is actually used. *Due to continued product improvement, the product illustrated in photos may vary slightly from the actual product. *Vehicle fitment is based on BMW 215LW differential applications. Differential specifications can vary by production date, transmission, drivetrain and market. If you are unsure about compatibility, please contact us before ordering. Unless otherwise specified, all Fully-Forged LSD units are supplied with the recommended 50/65° ramp configuration, offering the best balance between everyday drivability and performance. Motorsport product notice: This is a performance-oriented motorsport component. Some mechanical differential noise may occur during parking maneuvers or slow, sharp turns, particularly with the more aggressive 30/30 and 30/60 ramp configurations.