DIFF BEARING KIT
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**These kits are 100% genuine BMW parts, in BMW packaging, but you cannot buy them directly from BMW yourself .

A lot of customers (and even many professional mechanics) have never opened a differential. What exactly is inside?

We know that when we want to change gear ratios, you're going to purchase a ring and pinions set (crown wheel & pinion). By adding an LSD, you purchase one of the high performance options available, but like an engine - there are seals, bushings and bearings inside the diff that will need to be replaced when rebuilding.

Our exclusive kit includes all the seals, bushings and bearings you will need for the complete rebuilding of the Differential, including wear items like cone & bearings that BMW will not sell.

These are the same kits that we use when we rebuild differentials for our customers, so you know they have been tested for millions of real world street and track miles.

Whilst the differential is removed from the car, it is prudent to assess the condition of the differential mounts. it may well be cost effective to replace these at this time, due to age and condition. We can supply various brands of mounting bushes, please ask when ordering bearing kit.

PLEASE NOW REFER TO VARIATIONS SECTION ( RED LINK BUTTON AT TOP RIGHT) TO SEE OPTIONS AND PRICES FOR YOUR PARTICULAR VEHICLE.


Estimated Volumetric Shipping Weight : 6.00 Kg

 

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Quaife Engineering has been in the forefront of high performance transmission technology since 1965.

Their goals are always the same, to deliver outstanding quality and performance.

The QUAIFE ATB differential is designed to prevent the complete loss of drive that occurs with a conventional differential when one wheel slips. Whilst requiring some torque in the slipping wheel, the QUAIFE unit is progressive in action but never locks – controlled power is transmitted to all the driving wheels. Ideally suited to high powered front wheel drive systems, QUAIFE ATB differentials are also used in rear and four wheel drive vehicles where optimum traction is required. Installation is identical to the normal differential with bearing pre-loads and pinion mesh being restored to the original manufacturers’ settings. Servicing of the unit is simple as all gear pinions are free fitting and normal final drive lubrication oils are retained.

Benefits
-All QUAIFE differentials come with a Life Time Warranty.
-Maximises traction and minimizes wheel spin
-Proven in drag and circuit racing, rallying and road use
-Eliminates torque steer and snatching in fwd cars 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, from Alfa Romeo to Volvo
-Beware of cheap imitations!

More traction, more speed
As engine power outputs increase ever further, the ability to utilize this extra performance becomes more important. Wheel spin may look spectacular, but such losses of traction waste time either from a standing start or exiting a bend, whether driving on the road, circuit, rally stage or drag strip. Fortunately, QUAIFE’s patented Automatic Torque Biasing (ATB) Helical LSD differentialis an effective, well-proven, low-cost solution.

As a direct replacement for the standard, factory ‘open’ differential, QUAIFE’s ATB Helical LSD unit can transform the performance of your car. Unlike a conventional plate-style limited slip unit, QUAIFE’s ATB Helical LSD unit relies on gears, rather than clutch plates for its operation.

That means it is much smoother in operation, because unlike a conventional plate-style LSD, it never locks harshly with a set pre-load of wheel slip across the driven axle. Rather, it automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree and never locks.

To the driver (especially of a front-wheel drive car) the results are significant performance improvements;- superior, controllable traction without the harsh steering wheel snatch or torque steer that have long been associated with performance differentials. These traction benefits can also be utilised in rear wheel drive vehicles, while QUAIFE ATB Helical LSD units offer significant traction advantages fitted to the front of four wheel drive cars.

Reliability is total; the ATB Helical LSD units are designed using the latest CAD techniques and are CNC machined to ultra-tight tolerances from the very best CORUS steel billets. The completed units are then subject to rigorous in-house inspection on a tri-coordinate measuring machine before being dispatched to the customer.
Such quality means that unlike a conventional plate-style LSD the QUAIFE ATB Helical LSD unit requires no special maintenance or rebuilds, long lasting and it retains the standard method of lubrication, making for an easy, pain-free upgrade.
Proven in rallying, racing and on the road, the ATB Helical LSD differential offers safe, reliable,winning performance– everything you would expect from a QUAIFE product.


In an age when power and torque outputs are rising rapidly thanks to the adoption of ever-advanced technology, harnessing engine performance to use it effectively in a user-friendly manner is huge challenge for engineers and powertrain designers. The problem is simple one – how do you effectively control the delivery of power through the driven wheels to maximize traction and minimize wheelspin.

Different car manufacturers have adopted different approaches. Some front wheel drive platforms (particularly from Ford and Opel/Vauxhall) have adopted the electronic traction control route, which offers safety benefits, but tends to compromise driver involvement and enjoyment, particularly if the vehicle is used for trackday work.
Others – such as Mitsubishi and Subaru – have invested heavily in developing four wheel drive systems for their high performance derivatives and while these total traction systems afford obvious benefits, the negative factors such as high transmission power losses and excessive weight mean that they will remain very much a niche market.
Which leaves vehicle designers in something of a quandary, as they are faced with just two choices for an effective, user-friendly and low-cost traction control system on a two-wheel drive high performance car. Interestingly, in an increasingly electronic age, both of these systems rely on mechanical methods to improve traction.

In recent years the advantages of the Quaife ATB differentialhave been exploited by original equipment manufacturers in both front and rear wheel drive applications.

These include:
Dodge (V10 Viper sports car)
Dodge (Neon SRT-4 high performance sedan)
Ford (Focus RS high performance hatch)
GM F40 transmission (currently under development)

The Quaife Engineering Automatic Torque Biasing differential
The second mechanical method of improving traction is to use a Quaife Automatic Torque biasing differential. Rather than using clutch plates as a method of operation, the Quaife ATB uses sets of floating helical cut gear pinions that run in pockets and mesh during normal driving.

Should one of the driven wheels start to spin however, the helical gears start to generate a torque bias thanks to the axial and radial thrust of the helical gear pinions in their pockets. The result is a progressive transfer of torque away from the spinning side of the axle to the driven wheel, which is now capable of transmitting a greater proportion of torque.

i) Positive Dynamic Effects
Because the Quaife ATB differential’s design produces aprogressive transfer of torque away from the spinning wheel to the wheel that is capable of driving, the effect is far more benign to the driver. For rear-wheel drive use the benefits of the Quaife ATB diff are obvious –
excellent traction qualities, combined with a progressive action, making for a benign, effective and involving package for those seeking the ultimate in safe high performance vehicle dynamics.

This has been proven by the interest shown by from Dodge for the adoption of the Quaife differential as an optional extra for the Viper V10 sports car. In this application,the Quaife ATB copes happily with 525lb/ft of torque at just 4,100rpm.
In a front wheel drive car harsh snatching and torque steer are eliminated, so much so that it is not uncommon for a Quaife ATB differential to cope with 350lb/ft of torque through the front wheels in aftermarket road applications.

ii) Maintenance Free Performance
Unlike a plate style LSD the Quaife unit delivers performance without the need for strip downs and rebuilds. There are no plates or gears to wear or break and the ATB units retain standard vehicle lubrication.

PLEASE SEE PRICE LIST IN BELOW LINK, PLS CALL OR E-Mail us FOR ANY FURTHER INFO OR QUESTIONS.

Estimated Volumetric Shipping Weight : 20.00 Kg

 

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PINION IN ISOTROPIC SUPERFINISH
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Rtaio Table E46 M3 & E9x M3
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PLEASE NOTE : THESE PARTS ARE GENUINE BMW / BMW MOTORSPORT ITEMS, THEY ARE NOT THE CHEAPER AND INFERIOR FAR EAST MADE VERSIONS (THAT OFTEN BREAK) !! THE BMW MOTORSPORT (UNLESS WE ADVISE OTHERWISE) COME IN THE HARDENED FINISH

Need to alter the final drive gearing on your rear axle to suit new tuning modifications ? This is easiest acheived by swapping the internal gears within the rear differential housing to give either a higher or lower than factory final drive ratio .

A numerically higher ratio will give lower gearing, equating to increased acceleration but decreased potential top speed ....and vise versa.

MANY CARS CAN AFFORD TO LOSE SAY 10 - 25MPH TOP SPEED IN FAVOUR OF THE BETTER ACCELERATION AND OVERALLL "PULL" THAT LOWER GEARING WILL OFFER.

Made from hardened steel surpassing OEM specification.

We can offer almost any ratio for almost any diff, 188 and 210 cases, 14 and 12 mm bolt holes.

We can supply the gear sets either new or second hand at significant saving, all second hand parts have been inspected and x ray tested.

Please contact us for best prices and availability, here is typical price selection :

- E36 and E46 M3 3.91 or 4.10 gear set £830.00 (BMW MOTORSPORT)
- E92 M3 £890.00

NOTE : For many applications we also offer these gear sets in the REM Isotropic Superfinish, at extra cost, please enquire. benefits are :

• Reduce Friction
• Increase Part Durability
• Improve Corrosion Resistance
• Reduce Wear
• Reduce Lubrication Requirements and Cost
• Improve Oil Retention Properties
• Reduce Contact and Bending Fatigue
• Improve Pitting Resistance
• Reduce Vibration and Noise
• Reduce Applied Torque Requirements
• Produce a Uniform Surface Finish
• Produce a Superior Surface Finish
• Eliminate Break-in
• Extend Component Life
• Reduce Metal Debris
• Reduce Part Failures
• Minimize Overheating


Estimated Volumetric Shipping Weight : 17.00 Kg

 

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When changing rear differential gear ratio sets it can often be difficult or impossible to remove the existing side bearings without damaging them, so in most cases it is simpler to purchase new bearings at the same time as the gear set.

Includes housings.

We offer these bearings for most BMW models, please contact us for details prices.

PRICE EXAMPLE :

- E46 M3 £125.00
- E39 M5 £220.00


Estimated Volumetric Shipping Weight : 10.00 Kg

 

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We are official agents for Wavetarc LSD products.
Prices fluctuate for a number of reason, please call or E-Mail us for any info and best pricing.
We will beat any other quote !

*** Why is the Wavetrac better than all other Automatic Torque Biasing Limited Slip Differentials, or ATB LSDs?

To best understand how the Wavetrac® is truly different from the other gear differentials on the market, you first have to understand the primary problem that the Wavetrac® solves.

The problem: Loss of drive during zero or near-zero axle-load conditions.

Zero axle-load is a condition that occurs during normal driving, but creates the most noticeable problems when driving in extreme conditions. Zero or near-zero axle-load is the condition that exists when there is ‘no-load’ applied through the drivetrain, when one drive wheel is nearly or completely lifted (often in aggressive cornering). It also occurs during the transition from engine driving a vehicle to engine braking and back, even with both drive wheels firmly on the ground.

Here’s how that loss of drive hurts you:

1) If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel.

2) During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing.

Why does this happen?

All gear LSDs (including Torsen®, Truetrac®, Quaife®, Peloquin, OBX, MFactory etc.) work in basically the same manner: they divide the drive torque between the two axles, applying drive to each side, up to the available grip of each tire. The amount of drive torque one wheel can get over the other is described as the bias ratio, a measure of the torque split across the axle.

Standard, open differentials have a bias ratio of 1:1. They can only apply as much drive torque as there is available traction at one wheel. When one wheel loses grip, the total available drive is lost as well (at a 1:1 ratio). All your power goes out the slipping wheel - along the path of least resistance.

Torque biasing differentials offer increased bias ratios over open differentials. For example, if a diff has a bias ratio of 2.5:1, then it can apply drive torque to the wheel with the most traction (gripping wheel) at 2.5 times the traction limit of the wheel with the least traction (slipping wheel). This is a significant improvement over an open diff most of the time.

The problem is that when one tire has little to no grip (wheel spinning, suspension unloading under corner, bumpy roads), the other wheel gets ZERO DRIVE, because (basic math here): 2.5 x 0 = 0.

Lift a wheel (or substantially unload a wheel) and you get zero axle-load on that side - that means that during the time the wheel is unloaded, the typical diff will NOT power the wheel that’s still on the ground. No matter how high the bias ratio, you get no power to the ground.

During the transition from accel to decel, where you have near zero torque on the axle, even if the wheels are on the ground, the typical diff is unable to begin applying drive torque until AFTER the zero torque condition is over. While this condition is generally short-lived, the fact that most diffs can do nothing during that time means that there will be a delay once the zero torque condition stops - creating a reaction time in the driveline.

The Wavetrac®, however, is different:

The innovative, patented, Wavetrac® device in the center of the diff responds during these exact conditions when zero or near-zero axle-load occurs. At or near zero axle-load, the axles (and therefore each side gear in the diff) start to turn at different speeds.
This speed differential causes the Wavetrac® device to step into action:

Precisely engineered wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart.

Very quickly, this creates enough internal load within the Wavetrac® to STOP the zero axle-load condition.

The zero axle-load condition is halted, and the drive torque is applied to the wheel on the ground (the gripping wheel)… keeping the power down.

Some gear differentials rely solely on preload springs to combat loss of drive. The drawback is that you can’t add enough preload to prevent loss of drive without creating tremendous handling and wear problems at the same time. So, to avoid these problems, the preload from ordinary spring packs must be reduced to a level that renders them ineffective at preventing loss of drive. The Wavetrac® is the only differential that can automatically add more load internally when it’s required.

In the case where both wheels are on the ground during zero axle load, such as during a transition to deceleration, the Wavetrac® device is able to prepare the drivetrain for when the zero torque condition stops, eliminating the delay seen with ordinary gear diffs.

What this means for you as a driver is that power is delivered to the gripping wheels for more time and in a more constant manner – making you faster and improving stability.

The Wavetrac® truly is different - and its innovative features can make a real difference in your car’s performance.

Here’s something else you won’t find in any other design:

The Wavetrac® diff’s behavior can be altered in the field to suit your needs. It comes standard with carbon-fiber bias plates for the best all around performance and lifetime durability. All other ATB LSDs like the Quaife run the helical gears on the diff casing, meaning the gears/housings can polish theirselves or transfer material, making for inconsistent performance. Changeable plates using materials with different friction coefficients to fine-tune the bias ratio are sold separately.

These bias plates provide a mechanism to tune the response of the differential as a function of applied torque load. The applied torque load manifests itself as an axial load from the differential pinions into the housing. This axial force is then considered a normal force into the bias plate, and as a function of the effective coefficient of friction, provide a resistive torque to the rotational motion of the differential pinions. The resistive torque will add to the resistance of relative rotation of all components within the differential. The resistive force, however, is non-uniform since it is a function of the axial load from the differential pinions. The unbalance of the resistive torque will manifest as non-uniform energy absorption within the differential causing a bias ratio.

Here are more features that make Wavetrac® even better:

The new Wavetrac® Differential brings current gear technology to the market.

Internally, its gear tooth forms are optimized for strength and improved oil film retention over competitive designs.

Our gear package is smaller, reducing overall mass, yet is more durable since particular attention was paid to the tooth strength - optimized for high torque conditions.

Attention was also paid to the side gear/axle interface, putting as much material thickness as possible in this critical area - most important when power levels get high.

Each Wavetrac® Differential is crafted from the highest quality materials available.

The internal gears are made from high strength 9310 alloy steel.

The diff bodies are machined from case-hardened steel billet.

To complete the package, every Wavetrac® differential is built exclusively using high quality, high strength fasteners from ARP®, the world leader in fastener technology.


Estimated Volumetric Shipping Weight : 1.00 Kg