Quaife ATB BMW Limited Slip Differential Conversions
The Quaife ATB Differential provides significantly improved traction and handling for powerful rear-wheel drive cars, and is a must-have upgrade for BMW owners looking to maximise the potential of their machines.
Once installed, drivers will notice an immediate difference as the Quaife's ATB design automatically biases torque across the axle to the wheel with most grip. Unwanted wheel-slip is greatly reduced, and the driver is able to put the power down in a controllable and seamless fashion.
How is the Quaife ATB Differential superior to other LSDs?
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 differentials (such as BMW's M-Performance LSD).
The Quaife ATB;
- uses no wearing parts, so performance will not deteriorate over time
- requires no maintenance or servicing
- comes with a lifetime warranty
- offers a progressive deployment of power by biasing torque rather than locking
- is capable of biasing 80% of torque to the wheel with more grip instead of a fixed locking percentage
- works seamlessly with all standard components and electronics
Will it invalidate my BMW warranty?
The Quaife ATB will not invalidate your BMW warranty!
We have been directly responsible for the sale of over 5,000 Quaife ATB Differentials for BMWs worldwide, and not one of these has resulted in BMW claiming a fault or defect was as a result of the Quaife ATB installation.
BMW would not cover any defect with the differential itself of course, given it has been modified, but this is now covered by our own warranty and Quaife's lifetime guarantee.
"Through second and third gear corners, the differential tenses up in such a way that not only is drive preserved on either side of the car but also the driver has an instinctive and unusually well-defined awareness of the limits of grip and traction."
"The car's natural balance is easier than ever to exploit, the differential loading up as soon as you ease back onto the power, and the rear axle less perturbed by mid-corner bumps or undulations."
"In certain circumstances the open diff allows the M140i to spin its unloaded rear wheel which obviously leads to a less than controlled rear end. A lack of traction means that the engine's power cannot be delivered to the road..."
"The car will slide like Ari Vatanen’s Mk2 Ford Escort if you want it to, but it’s actually more satisfying to hold the little coupé in modest, neat and perfectly balanced drifts away from tighter corners; the kind of slide that still pings you along the next straight with real impetus."
"Where you do notice a difference is with the DSC off. On a tight, wet uphill bend where the standard car would have just felt untidy and a bit frustrating, this car simply spins up its rear wheels in unison and arcs round in an easily gatherable slide..."
with the LSD fitted, the M135i is wonderfully controllable, the rear end breaking away in a completely fluid and controllable way. It's brilliant.."
What purchase options do I have?
We offer a global service that allows customers to ship their differentials to us for Quaife LSD Conversion. We have also created an Exchange program to avoid conversion downtime for customers;
Exchange QUAIFE LSD Differential
The Exchange QUAIFE LSD Differential by Birds is a complete BMW differential equipped with a Quaife ATB LSD. We offer to install or ship the units in exchange for the customer’s existing standard differential.
This is only offered to customers with vehicles under 60,000 miles. Customers with vehicles over this mileage will either need to have their original differential converted (we will need the differential here for 5 working days to complete the conversion), or purchase an Exchange QUAIFE LSD with High Performance Bearings.
Worldwide shipping is available. If we ship the Exchange QUAIFE LSD Differential to the customer first, a £500 (excl.VAT) surcharge is charged until we receive the customer's original differential in return.
Birds guarantees the bearings and all other internal wearing parts in their Exchange QUAIFE LSD Differentials for 24 months, and the Quaife ATB itself comes with a limited lifetime warranty.
Exchange QUAIFE LSD & High Performance Bearings
The Exchange QUAIFE LSD with High-Performance Bearings is a complete BMW differential equipped with a Quaife ATB LSD and all new high-performance bearings, in exchange for the customer's existing standard differential.
The uprated tapered bearings offer a 44% increase in load capacity compared to the standard BMW ball bearings, providing much more durability and a longer lifespan. We have these specially made in the UK. For more information on these bearings, click here.
This is offered to customers with vehicles of all mileages.
Worldwide shipping is available. If we ship the Exchange QUAIFE LSD with High-Performance Bearings to the customer first, a £500 (excl.VAT) surcharge is charged until we receive the customer's original differential in return.
Birds guarantees the bearings and all other internal wearings parts in the Exchange QUAIFE LSD with High-Performance Bearings for 36 months, and the Quaife ATB itself comes with a limited lifetime warranty.
Can I buy the QUAIFE LSD only?
Yes, we also offer QUAIFE LSD Conversion Kits. However, the reason we offer our exchanges is due to the difficulties of installing an LSD into these BMW differential housings.
In 2007, BMW began welding the crownwheel gear to the open differential instead of bolting them together in many of their models. This means that the crownwheel gear must be machined off and drilled so that the Quaife LSD can be bolted onto the crownwheel. It requires specialist set up and access to machinery. While this a routine procedure for us, most workshops can't or won't want to carry out this work.
We do have a number of Quaife BMW Distributors around the world that are also capable of carrying out this process, including the USA, Russia, Australia, China, and many European countries. We can also provide technical drawings and installation guides.