Quaife ATB limited slip differential
for BMW and BMW M cars
- Delivers the complete power of your engine onto the road!
- Amazing traction and on-limit control!
- Highest quality and engineering!
- High Tech – Made in Great Britain
- Unbeatable price / performance ratio!
- Worldwide lifetime guarantee!
The Quaife ATB (automatic torque-biasing) differential is a unique type of limited-slip diff that provides significantly improved traction for BMW and BMW M. 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’s clever design uses helical scroll gears that automatically bias torque to the wheel with more grip during instances of traction loss, offering a more progressive deployment of power and without wearing or requiring maintenance.
High-performance rear-wheel drive cars become much more controllable during moments of oversteer, enabling drivers to exploit the full potential of their machines for the first time, leading to a more exciting, rewarding and rapid driving experience.
Visit the world’s largest BMW and BMW M limited slip differential applications list.
PDF – product and price list
The Quaife design will work flawlessly with all OE components, will not void your manufacturer’s warranty, and comes with its own worldwide lifetime guarantee!
NOVATUNE Germany are an authorized Quaife distributor.
Do you need a limited-slip differential?
If you think limited-slip diffs are just for track cars, think again…
All standard BMW and BMW M are fitted with an “open differential” – a device that allows the driving wheels to turn at different speeds. The problem with the open diff is that it can only ver apply the same amount of torque to both driving wheels, and when a wheel slips, it will only put through the amount of torque it requires to power that spinning wheel (i.e. very little).
The result is an inability to apply power to the ground during traction loss. With road cars, quick driving in slippery conditions or on bumpy road feels restricted as the open diff spins away power wastefully. Powerful cars with high torque outputs can be “undriveable” for enthusiasts.
Additionally, BMW and BMW M use various electronic traction systems that curb power to the driving wheels during traction loss (indicated by the flashing traction light on your dashboard). The BMW Dynamic Stability Control system (DSC) is designed to “curb the engine output and stop slip on the wheels”, but often serves as a further frustration when trying to push on.
Fortunately there are clever differentials that will transfer torque to the wheel with more traction rather than take it away… watch the video below to see more about how an open differential works and types of clever differentials:
How is the Quaife ATB superior to other limited-slip differentials?
RT Quaife Engineering Ltd is a global leader in the performance automotive drivetrain industry, supplying motorsport users, volume OEM and commercial customers with a wide variety of precision engineered products for cars, motorcycles and specialist use vehicles. From clubman rallying up to Formula One, tens of thousands of automotive and motorcycle users depend on Quaife products to maximise their vehicle’s performance on a daily basis, including sequential gearboxes, automatic torque biasing differentials and associated drivetrain components.
Quaife ATB differential vs clutch-plate limited-slip diff
Quaife’s ATB limited-slip differentials were designed to overcome the flaws of conventional ‘clutch-plate’ limited-slip diffs, offering an innovative and cost effective way to maximise your Mercedes’ or BMW’s traction.
Clutch-plate LSDs (BMW M-Performance, Drexler, OS Giken, etc) operate using an internal spring pack and set of clutches that limit the amount of rotational difference between the driving wheels in low traction conditions. But employing this kind of LSD can be a costly investment. The wearing of clutches means it will eventually need replacing, and it is not uncommon for some to reach their useful life as low as 30,000 miles. Due to their finite life, many of them cannot be guaranteed for more than 12 months. As well as needing to “run them in”, special lubricant changes are required throughout its life.
Additionally, if high locking percentages are used, they can cause abrupt locking of the rear axle and make the car difficult to control. Many involved in BMW motor racing (including those participating in the BTCC) converted over to the Quaife ATB from a locking LSD because of significant “snap-oversteer” out of slippery turns.
The Quaife uses a patented gear-only design that automatically biases the torque across the axle depending on which wheel is enjoying the most grip, helping to maximise traction in varying conditions. Compared to the clutch-plate LSD it is very progressive and predictable during moments of oversteer, never locking or snapping, making it the perfect differential for RWD road cars.
The Quaife design utilises non-wearing internal scroll gears so no maintenance or special lubrications are required, and all Quaifes are guaranteed to last the life of the car – backed by a limited lifetime warranty.
Watch this awesome video! Chris Harris tests Birds E92 335i, the first ever to be fitted with a Limited Slip Differential (LSD).
His final comments are priceless.
What is a welded differential?
You may have heard that your BMW or BMW M could have a “welded differential”.
A ‘final drive’ or ‘rear axle drive’ (also known in the U.S as a “core” or “pumpkin”) refers to the complete unit that sits between the driving wheels, distributing torque from the prop shaft to the drive shafts. Inside of the final drive you have a number of components, including the pinion gear, the crownwheel gear (also known as a “ring gear”), and the differential itself. The final drive as a whole is often referred to as the differential outside of specialist circles.
The crownwheel gear is mounted to the internal differential. When installing a limited-slip differential, you are replacing that differential only. Welded differentials in BMWs Traditionally, crownwheel gears have always been bolted to differentials. This makes it easy when installing an LSD, as you can simply unbolt the original differential and bolt the LSD on in its place.
However, in 2007, BMW began welding the crownwheel gear to the differential in some of their models. This means that specialist machining and set-up is required to part the crownwheel from the differential, and holes drilled into the crownwheel, before a Quaife LSD can be bolted on.
The majority of workshops either do not have the capabilities or do not have access to this kind of machinery. So we have created an exchange program for the convenience of our customers. We can provide an Exchange Quaife BMW Final Drive – a prepared Quaife-converted final drive that we can install or ship out in exchange for the customer’s standard final drive. This avoids machining downtime, and any risks for other workshops. A surcharge deposit will be required if we ship out the exchange drive first, and then refunded upon return of the customer’s original final drive. Customers have the choice of keeping their original.
Quaife Limited Lifetime Warranty
The Quaife ATB Differential comes with a worldwide limited lifetime warranty.
If the Quaife is being installed by another workshop, we can provide comprehensive installation instructions to help avoid mistakes during the conversion, and can also provide technical support over the phone. Errors during installation can affect the warranty. If you are intending to use the differential for racing or drifting, please contact us first to discuss your requirements.
How does it affect your manufacturer’s warranty?
Installing a Quaife ATB differential will not affect other components on the car covered by your manufacturer’s warranty.
We have been directly responsible for the sale of over 3,000 Quaife ATB differentials for BMWs and Mercedes worldwide, and not a single one of these has resulted in BMW or Mercedes claiming a fault or defect was as a result of the Quaife installation.
Product reliability is of paramount importance to us. We will only offer products that are guaranteed to affect BMW ownership and driving pleasure in a truly positive way.