BMW M140i, M240i, 340i and 440i QUAIFE ATB Limited-Slip Differentials now available!

The popular QUAIFE ATB Limited-Slip Differential is now available and IN STOCK for the F20 M140i, F22 M240i, F30 340i and F32 440i, exclusively at BIRDS.

The Quaife ATB Differential provides significantly improved traction and handling for powerful rear-wheel drive cars, and is an absolute must-have performance upgrade for keen drivers of these torquey, grip-limited BMWs.



Only the M-Powers arrive from the factory properly equipped with a mechanical limited-slip differential. Unfortunately, those of us who choose a slightly more practical and less aggressive BMW may well find that the standard power of the car easily overcomes the amount of traction available. This is especially true with recent models, equipped with turbocharged engines that produce high torque outputs, and often equipped with run-flat tyres and stiff suspensions. Lack of traction will of course worsen when road conditions become more slippery or bumpy too.

Fortunately Birds have again been quick to develop a solution around their popular Quaife ATB Differential, and now offer them installed at their U.K premises at £2016 (inc VAT). 

Uniquely, Birds also offers a plug & play solution for customers worldwide - complete Quaife ATB-equipped Differentials in exchange or outright (subject to stock) are available directly from Birds, and we can provide comprehensive installation guides and technical support for local workshops.

Contact us for more information

Quaife Price List

Why choose Quaife?

British manufacturer RT Quaife Engineering Ltd is a global leader in the automotive drivetrain industry, supplying motorsport users, volume OEM and commercial customers with a wide variety of performance products since 1965. Their innovative Quaife ATB Differential, arguably their most famous product, was chosen by FORD to use as OEM in their Focus RS model - a testament to their reputation for quality and reliability.

Once installed, drivers will notice an immediate difference as the Quaife's patented ATB design automatically biases torque across the axle to the wheel with most grip. Unwanted wheel-slip is greatly reduced, enabling drivers to exploit the full potential of their machines for the first time, leading to a more exciting, rewarding and rapid driving experience.

Widely regarded as the differential upgrade of choice for road car owners, the Quaife ATB was designed to overcome the flaws of conventional clutch-plate limited-slip diffs such as Drexler, OS Giken, and BMW's own M-Performance differentials.

The Quaife ATB;

  • offers a progressive deployment of power, never locking or snapping, allowing rear-wheel drive cars to become more controllable during moments of oversteer.
  • is silent and smooth in operation. 
  • requires no maintenance, never wears, and is backed by a limited lifetime warranty.
  • works perfectly with all standard components and electronics, and will not invalidate the manufacturer's warranty.

View our endless testimonials and  editorials about Quaife ATB Differentials for BMWs!

British manufacturer RT Quaife Engineering LTD have had a reputation for quality and reliability since 1965.

Quaife's unique and patented gear design allows for progressive traction without wearing or requiring maintenance.

Birds can install/supply plug & play complete Quaife ATB equipped Differentials in exchange to eliminate conversion downtime.

Differential swap is a standard BMW procedure and takes 2-3 hours.


ABOVE: BBC Top Gear's Chris Harris tests the Quaife ATB in Birds' E92 335i during his Autocar days...