BMW M140i / M240i / M135i / M235i Quaife ATB LSD Upgrade – Fully Installed Differential

Upgrade your BMW with a fully built final drive featuring a brand-new Quaife ATB (Automatic Torque Biasing) Limited-Slip Differential.

This is a complete, ready-to-fit unit — the Quaife differential is professionally installed into the final drive, allowing for a straightforward installation with no additional setup required.

Designed for both road and performance use, this upgrade transforms traction, stability, and power delivery — especially on tuned or higher-powered vehicles.

🚗 Why Upgrade to a Quaife ATB?

The Quaife ATB is widely regarded as the best option for fast road and performance BMWs, eliminating the common drawbacks of traditional clutch-type LSDs (including OEM M Performance units).

Instead of aggressive locking, the Quaife uses a helical gear system to seamlessly transfer torque to the wheel with the most grip — giving you maximum traction without compromising drivability.

🔥 Key Benefits

• Improved Traction & Grip
  Reduces wheel spin and puts power down effectively — especially when exiting corners or in poor conditions
• Maintenance-Free Design
  No clutches, no plates, no servicing required
• Smooth & Silent Operation
  No harsh engagement — perfect for daily-driven cars
• OEM Compatibility
  Fully works with factory electronics and systems
• Predictable Handling
  Progressive torque transfer for confidence-inspiring performance
• Limited Lifetime Warranty
  Backed by Quaife for long-term peace of mind
  

💰 Core Exchange Deposit (£200)

This product includes a £200 refundable core deposit.

You have two options:

• Return your original differential → your £200 deposit is fully refunded
• Keep your original differential → the £200 deposit is retained

Your original unit must be in good working condition, with no bearing noise or oil leaks. Refunds are processed promptly after inspection.

📞 Need Help?

If you're unsure about fitment or have any questions, feel free to get in touch — we’re happy to help.