Quaife QDF20N BMW Large Case Welded ATB Helical Gear LSD

The Quaife QDF20N automatic torque biasing (ATB®) limited-slip differential for BMW models fitted with the welded large case differential stands as the ultimate traction upgrade for any vehicle equipped with a standard factory open differential. Often imitated but never surpassed, the Quaife ATB® delivers enhanced performance, providing improved traction, handling, and braking in all driving conditions. Trusted by road car enthusiasts and motorsport competitors alike, this precision-engineered British-made differential is a direct replacement for standard differentials and is compatible with a wide range of front, rear, and four-wheel-drive vehicles. Since its introduction in the 1980s, the Quaife ATB® has proven its durability and effectiveness in high-performance environments such as rallying, circuit racing, rallycross, and Time Attack. Enhance your vehicle's control and enjoy superior performance, whether on the track or the open road. Lifetime Warranty: The Quaife ATB® comes with a lifetime warranty for both motorsport and road use, ensuring long-lasting reliability. British Quality Manufacturing: Proudly made in Great Britain, the Quaife ATB® is produced to rigorous ISO9001-2008 standards for superior performance. Trusted by Leading OEMs: Chosen by top manufacturers with zero warranty replacements reported. Zero Maintenance Components: Gear-operated with no service parts to replace—ever, ensuring hassle-free ownership. Reduces Torque Steer & Improves Handling: Dramatically minimizes unwanted torque steer, understeer, and oversteer for a smoother driving experience. Seamless Compatibility: Designed to work flawlessly with modern electronic stability and traction control systems in road cars. Enhanced Braking for FWD Vehicles: Improves braking performance on front-wheel-drive cars by reducing lock-up and minimizing ABS intrusion through efficient torque transfer. Safe and Smooth Operation: The Quaife ATB® delivers progressive, seamless action without ever fully locking, ensuring safe and controlled driving. Direct Replacement: A straightforward, direct swap for the factory ‘open’ differential unit, with no modifications required. Compatible with Standard Lubrication: Retains your vehicle's standard axle lubrication system and maintenance schedule. Proven Performance: With over 100,000 units sold globally since the 1980s, the Quaife ATB® is a trusted solution for improving vehicle traction and control.