Quaife ATB BMW Limited Slip Differential Conversions for M-Power BMWs
The famous Quaife ATB limited slip differential is one of the world's most popular performance products for BMWs.
This unique device absolutely transforms the way your car applies power to the road, offering a stunning increase in traction, acceleration, cornering speeds and handling. 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.
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There's something odd going on at BMW.
The last production BMW to be sold with the option of a limited slip diff was the E36 328i. Since then, LSDs have been the preserve of the fabulous M-Power cars. Unfortunately, even the M-Differential suffers from issues.
Firstly, they wear out. Given that the M-Diff is a clutched differential, the performance deteriorates with time and mileage, and the locking effect gradually reduces to nil. Secondly, BMW did quite a good job designing the maximum possible number of clutches into the LSD, to prolong the life as far as possible. Unfortunately, this leaves very little room for the differential gears, and the size of those components has been reduced so much, that they are incapable of handling the torque for very long. The bearing spindles often wear out, and this is the cause of the clicking/clunking that these differentials often exhibit on tight turns. Also the right hand output shaft is very short, and is therefore not stable in the differential bearing journals, as a consequence of the very high load moment on this shaft. If you have a noisy or ineffective M-Differential, simply grab the right hand output shaft. If you can feel lots of movement, then the differential is on the way out. With certain models, BMW offer a special gear oil, which can reduce these noises, but unfortunately, it cannot repair any damage done.
Replacement M-Differential, anyone ?
The replacement cost of an M Differential runs into several thousands of pounds. Replacing something that can last as little as 30,000 miles with an expensive standard part, that may not last longer than the original, seems a bit short sighted. Given that some of the older cars have depreciated to a level that cannot warrant this expense, a more robust solution had to be found.
Th Quaife solution.
Birds have developed a solution around the Quaife ATB Differential. This renowned device is capable of transmitting any amount of power and torque. Quaife do not place torque limits on these devices. It is absolutely the case that the surrounding parts will fail long before the Quaife ever fails. Quaife are therefore able to offer a Lifetime Warranty on every Quaife ATB Differential. The Quaife differential replicates the performance of the M-differential so closely we would defy anyone to tell the difference. Apart from the price. And the longevity.
Of course the Quaife conversion has added benefits too.
- Elimination of the unreliable short right-hand output shaft on M-Differentials
- Less than half the price of a complete final drive from BMW
- Available for all current M-Power cars
- ALL Quaife differentials supplied by Birds come with a Life-time Warranty
- Maximises traction and minimizes wheel spin
- Proven in drag and circuit racing, rallying and road use
- Eliminates snatching compared to conventional LSD
- Maintenance free design and retains standard axle lubrication
- Produced from British Steel billets throughout
- CAD designed and CNC machined then inspected to ISO 9001 standards
- Used by Ford, GM and Daimler-Chrysler as original equipment
- Massive range available, more than 300 BMW Applications
- Proven in thousands of BMWs worldwide, with no failures.
What’s in the kit?
It can vary. Nearly all M-Power BMWs will require a new pair of output shaft bearings since they are almost impossible to remove without damaging, and all of the models after the E39 M5 (including the E46 M3) will also require a new pair of equally sized output shafts so that the Quaife can sit centrally in the housing.
1x Quaife-BMW ATB Differential
2x Quaife-BMW Output Shafts
2x Quaife-BMW Output Shaft Seals
2x Output shaft bearings
Installation Instructions
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