BMW Differential and Gearing Upgrades for BMW 5 Series E39 (1996-2003)

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Upgrading various parts of the differential can have tremendous benefits in your car's performance. It's easy to forget that the differential is a source for making your car faster and handle better so it's often overlooked. The engine is not the only place to make the car faster. Our differential options vary from gearing upgrades to limited slip conversions. You can purchase the ring & pinion gear sets on their own (professional installation required) or have us build a diff around your own specifcations. The options are almost endless! Every custom-built diff is fully rebuilt with seals and bearings. We also design and supply bushing options to reduce driveline wind-up, finned differential covers for better cooling, and more!

Ratio Changes - Changing the differential gearing is one of the best and most-effective upgrades you can make on any BMW (old or new). By using a shorter (numerically higher) final drive ratio you are increasing your RPM relative to road speed - this puts you in a more powerful RPM range than before! Since you're in a 'meatier' part of the power band you're now putting down more power/torque to the ground. If you can trade outright top speed for faster acceleration at daily speeds then this is the perfect upgrade for you.

Limited Slip Upgrades - Sadly, many BMWs today are not equipped with a limited slip (posi-traction) differential. BMW has tried to compensate by using traction control that cuts power at the engine or applies the brakes to retard wheel spin (or a combination of both). But nothing beats the function and feel of a a true LSD which may be why BMW continues to use them in M cars. Our LSD upgrades can be done a number of different ways - a factory-type limited slip unit with either 2 or 3 clutch packs, helical type, OS Giken unit, or something truly custom. We can also vary ramp angles and setup to change the limited-slip behavior under acceleration, deceleration, and cornering. Need a custom diff? Call or e-mail to have a quote.

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Turner Titanium Magnetic Differential Drain Plug - M22x1.5
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:593924
Part#: 027030TMS01
In Stock
Sale - Save 25% $ 89.99

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Sale - Save 25%
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$ 67.49 USD
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When both extreme-duty protection and saving every gram matters: the Turner Magnetic Differential Drain Plug.
ECS - Corporate Logo
T#:366828
Part#: 009314ECS01A
In Stock
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$ 47.24 USD
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You use a magnetic drain plug for your engine oil, right? Why not apply the same proactive thinking to the differential too? This is a direct replacement magnetic differential drain plug for your BMW. It will catch and retain fine and larger metal particles in your diff oil. If you're proactive in your diff oil servicing, you will catch a minor issue long before it becomes a headache. Diff drain plug includes one sealing o-ring. Direct replacement for Genuine BMW part number(s): 33117525064, 33110308370, 33110152626
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Team MFactory - Corporate Logo
T#:379412
Part#: MF-TRS-05E46A
In Stock
$ 999.99 USD
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$ 999.99 USD
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The best way to gain a prominent advantage over the competition is to do it with the MFactory Helical Limited Slip Differential. The smooth consistent distribution of power to the wheels with the MFactory Helical LSD puts the power to the ground and maximizes your vehicle's traction. A must for any car be it street, strip, or track. What exactly does an LSD do you ask? well without an LSD your car is actually 1 wheel drive, in that it can't supply torque to both wheels at the same time and will only supply torque to the wheel with less grip, which is what the shortfall is to an open differential (what most vehicles have). An LSD only lets the wheels spin at different speeds by a limited amount (typically this is a percentage difference) which is when the differential locks and both wheels get power. This is not how locked differentials work such as in off road trucks which supply equal torque and rotational speed to both rear wheels at the same time, which can cause issues with handling.
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Metal Plate Limited-Slip Differential - 1.5/2.0 Way, V2
For vehicles with an automatic or manual transmission with a Final Gear Ratio of 3.15 ...
Team MFactory - Corporate Logo
T#:379410
Part#: MF-TRS-10E90B
Back Ordered
$ 999.99 USD
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$ 999.99 USD
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The best way to gain a prominent advantage over the competition is to do it with the MFactory Metal Plate Limited Slip Differential. The smooth consistent distribution of power to the wheels with the MFactory Plate LSD puts the power-to-the-ground and maximises your vehicle's traction. This 2-way differential will provide torque transfer during both acceleration and deceleration. This means that regardless of whether there is load (throttle) being applied to the differential or not, it will lock up during slippage. Ideal for those with track use in mind. What exactly does an LSD do you ask? Well without an LSD your car is actually 1 wheel drive, in that it can't supply torque to both wheels at the same time and will only supply torque to the wheel with less grip, which is what the shortfall is to an open differential (what most vehicles have). An LSD only lets the wheels spin at different speeds by a limited amount (typically this is a percentage difference) which is when the differential locks and both wheels get power. This is not how locked differentials work such as in off road trucks which supply equal torque and rotational speed to both rear wheels at the same time, which can cause issues with handling. Features: Forged and Cryo-Tempered for unsurpassed toughness Advanced Shot Peening technology for increased surface hardness Coil Spring preload system ensures minimal power loss and maximum response Lower initial pressure ensures maximum durability and chatter-free operation Fully rebuildable with adjustable lock (80-100%) and option for different cam types Available in 1.0, 1.5, and 2.0 way options
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ECS - Corporate Logo
T#:583896
Part#: 000920ECS01
In Stock
Sale - Save 25% $ 42.99

This product was last offered at the strikethrough price on
06-14-2026

$ 32.24 USD
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Sale - Save 25%
$ 42.99

This product was last offered at the strikethrough price on
06-14-2026

$ 32.24 USD
Free Shipping on orders $49 and up

Ensure the longevity of your BMW's drivetrain with ECS Tuning's Magnetic Plugs. These plugs are meticulously engineered in-house to provide a perfect fit and feature a permanent magnet attached to the plug body. The magnet effectively attracts and captures tiny abrasive and ferrous metal particles, preventing their circulation through lubrication systems. Metal particles can accumulate due to various conditions such as normal wear, machining operations, casting flaws, and stress usage, leading to excessive wear of vital components. ECS Tuning's Magnetic Plugs help alleviate this concern by trapping these particles, thus safeguarding the internal components of your drivetrain. With a convenient 17mm hex head design, these plugs eliminate the need for special tools required for OEM plugs.

Key Benefits:

  • Removes abrasive metal particles from drivetrain fluid
  • Prevents excessive wear to internal components
  • Meticulously engineered for a perfect fit
  • Features a permanent magnet for efficient particle capture
  • Convenient 17mm hex head design for easy installation
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Team MFactory Metal Plate Limited-Slip Differential (LSD) - 1.5 Way -...
For vehicles with an automatic or manual transmission with a Final Gear Ratio of 3.15 ...
Team MFactory - Corporate Logo
T#:379408
Part#: MF-TRS-10E90A
Ships in 7 Business Days
$ 999.99 USD
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$ 999.99 USD
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The best way to gain a prominent advantage over the competition is to do it with the MFactory Metal Plate Limited Slip Differential. The smooth consistent distribution of power to the wheels with the MFactory Plate LSD puts the power to the ground and maximizes your vehicle's traction. This 1.5-way differential works similarly to a 2-way in that it provides torque transfer during both acceleration and deceleration. However, the advantage over a 2-way is that it requires less force to lock the differential. This means that it will allow for different wheel speeds, like when cornering. A 1.5-way differential is typically the best option for track or street use, as it keeps from having one tire skipping or dragging.
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Powerflex Black Series - Corporate Logo
T#:379320
Part#: PFR5-526BX2
Ships in 1 Business Day
$ 102.99 USD
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$ 102.99 USD
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Differential bushings are responsible for keeping the differential in solid alignment while dampening drivetrain vibration. While OE rubber bushings are fine when they are new from the factory, aged and worn out rubber bushings create a multitude of issues that can range from annoying to dangerous. As a factory bushing ages, it begins to harden and become brittle. When this happens the bushing will actually shrink and allow for movement at the differential mounting point. At this point, the differential is free to shift under load causing a noticeable clunking noise under acceleration and deceleration and massively increasing the stress on the driveshaft and axles. Manual transmissions suffer the worst from this as it can make shifting difficult since the differential will shift when the clutch is engaged and disengaged.

By replacing these bushings with full polyurethane, the movement is eliminated since the mounting point is supported by a much stiffer material that will not harden or shrink over time. This means less stress on the driveshaft and axles and greater longevity of supporting components. 

Powerflex Black Series bushings are the ultimate in track and race bushings. Featuring 95A durometer polyurethane, Black Series bushings are 25% stiffer than street bushings. Engineered to perform, Powerflex performance polyurethane control arm bushings offer a supreme level of control, while still providing enough comfort for the street, with advanced polyurethane that reduces NVH that often accompanies lesser bushings. Expect improved acceleration response, more direct shifting feel and overall improved drivetrain composure with Powerflex performance polyurethane bushings.

Poweflex is a leading manufacturer of aftermarket suspension bushings. Using state of the art design and manufacturing, all replacement bushings are engineered to out-perform and out-last the ones that came in the car. Each line of bushings is meticulously tested and then re-tested to ensure perfect fitment and enduring quality through the life of the vehicle. A full lifetime warranty backs every one of their products and demonstrates the level of confidence and commitment Powerflex has to their customers. 

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Wavetrac - Corporate Logo
T#:363686
Part#: 30309170WKWVT
In Stock
$ 1,245.50 USD
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$ 1,245.50 USD
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Introducing the Wavetrac® Torque Biasing Differential by Turner Motorsport, the pinnacle of innovation for your BMW. This cutting-edge technology takes your vehicle's performance to a whole new level. With its patented design, the Wavetrac® differential is a trailblazer, automatically enhancing grip when navigating low-traction conditions. Its approach is truly revolutionary, setting it apart from other torque biasing differential designs.

Quality is the hallmark, featuring high-strength 9310 steel gears enclosed in case-hardened billet or forged steel bodies. Throughout the differential, ARP® fasteners are used, ensuring superior durability and performance. What's more, the Wavetrac® differential is virtually maintenance-free, promising a lifetime of service without the need for rebuilds.

To provide added confidence, all Wavetrac® differentials are backed by a transferable limited lifetime warranty, highlighting the product's reliability and longevity.

Important Note for Bolt Kits:

For vehicles equipped with a welded ring gear, the installation process requires the removal, drilling, and installation of the welded ring gear from your stock differential. This intricate task should be entrusted to a professional machine shop. To seamlessly install the ring gear onto the new differential, you'll need Bolt Kit ES4368731. It's imperative to consult your machine shop before purchasing this item and the necessary hardware kit.

Please be aware that no technical drawings or instructions are provided, underscoring the importance of verifying compatibility and ensuring correct installation with your chosen machine shop. Refunds or replacements will not be offered in the event of incorrect ring gear installation or differential failure due to improper installation.

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Team MFactory - Corporate Logo
T#:379407
Part#: MF-TRS-05E92
Ships in 4 Business Days
5% off MSRP $ 1,049.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 999.99 USD
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5% off MSRP
$ 1,049.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 999.99 USD
Free Shipping

Gaining a prominent edge over the competition is now within reach, thanks to the MFactory Helical Limited Slip Differential offered by Turner Motorsport. This Helical LSD ensures a seamless and uniform distribution of power to your BMW's wheels, significantly enhancing traction whether you're on the street, strip, or track. It's an absolute necessity for BMW enthusiasts.

Curious about the LSD's role? Without it, your car essentially operates as a one-wheel-drive machine, delivering torque solely to the wheel with less grip. This is where the Helical LSD shines, as it allows both wheels to receive power by limiting the speed difference between them, in contrast to the open differentials found in most vehicles.

Key Features:

  • 30-Day Feel the Torque™ Money Back Guarantee: An industry-first assurance that enables you to experience the difference. Furthermore, it comes with a Limited-Lifetime Warranty, offering peace of mind.
  • Forged and Cryo-Tempered: Engineered to deliver exceptional durability and extended lifespan, ensuring it can withstand the rigors of even the most demanding challenges.
  • Advanced Shot Peening Technology: Enhances surface hardness, making it well-equipped to handle the shocks experienced in competition-level drag racing.
  • Maintenance-Free Gears: Bid farewell to the hassles associated with special fluids or rebuilds commonly required for plate LSDs. It's designed for a trouble-free ownership experience.
  • Lock-Free Operation: Ensures there's no adverse impact on steering response, delivering a smooth driving experience.

Break-In Procedure: For optimal performance, it's recommended to change the fluid after the first 3-400 miles of use.

Please note that any defects or warranty claims should be directed to Team MFactory.

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Team MFactory - Corporate Logo
T#:381010
Part#: MF-TRS-DBE92S
Ships in 6 Business Days
$ 296.99 USD
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$ 296.99 USD
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Differential Rebuild Kit Plus by Team MFactory

Upgrade your BMW's differential with the Differential Rebuild Kit Plus by Team MFactory. Whether you've recently replaced your differential or upgraded to a Limited-Slip, it's essential to replace the hardware to ensure optimal performance. This comprehensive kit from ECS Tuning includes 10 Differential Ring Gear Bolts, new axle seals, and new differential bearings, providing everything you need for a complete differential rebuild. With high-quality components, you can trust this kit to support your new differential or rebuild your existing unit effectively.

  • Comprehensive kit includes Differential Ring Gear Bolts, axle seals, and differential bearings
  • Ensures optimal performance of your BMW's differential
  • Perfect for differential replacement or upgrades to Limited-Slip
  • High-quality components for reliability and durability
  • Provides all necessary hardware for a complete rebuild
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OS Giken - Corporate Logo
T#:1387
Part#: BM237-HA
Ships in 2 Business Days
$ 1,950.00 USD
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$ 1,950.00 USD
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The M Dynamic limited slip unit on the M3 is designed to be a pure street car differential. It's simply not up to the rigors of professional or amateur racing. The OS Giken Super Lock LSD is giant step up in from a stock M3 lsd unit. It's ready for the extreme conditions of racing, offers 100% progressive locking capability, and is able to do this while operating smoothly and quietly. It's use of advanced technologies that make it perfect for both street cars AND pro race cars... and everything in between. We're excited to be carrying the OS Giken LSD unit in our performance catalog, as we've been using them in our own Championship winning M3 race cars.

OS Giken incorporated revolutionary new ideas when developing the their own limited slip diff, utilizing their accumulated racing knowledge and experience and over 4 years of development. Their design uses an unprecedented number of friction plates (up to 28 total!) for better locking force, better engagement/disengagement, and less generated heat. The end result of their efforts is the OS Giken's OS Super Lock LSD which offers incredible durability and reliability on street and track driven BMWs. The use of highest quality materials, precise machining, forged gears and sound engineering makes this LSD durable and reliable enough for road racing performance (which we can personally vouch for!). This is such a great design, in that it can be used in any situation -- whether it's for a street car, or a 100% Professional race car. Zero break-in required. Super smooth and quiet engagement, and 100% progressive locking capability. Professional installation is recommended.

This Limited Slip Differential Unit fits the following BMWs:
2001-2006 E46 M3 coupe & convertible
2008-2013 E9X M3 coupe & convertible
1991-1995 E34 M5 sedan
1999-2003 E39 M5 sedan
2006-2008 E85 Z4M Z4 M Coupe, Z4 M Roadster
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Powerflex - Corporate Logo
T#:34549562
Part#: PFR5-526H
Ships in 1 Business Day
$ 93.99 USD
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The Powerflex Rear Differential Rear Mount Bushings for the BMW E39 5 Series are designed to provide a significant upgrade to the vehicle's rear differential system by replacing the stock rubber bushings with high-performance polyurethane. This enhancement leads to improved handling, stability, and durability.

Key Benefits:

  1. Enhanced Differential Control: The stiffer polyurethane material reduces unwanted movement and flex in the differential mount, ensuring better alignment and stability under load. This translates to improved power delivery and handling during cornering and acceleration.

  2. Increased Longevity: These bushings are crafted to resist wear and degradation from oil, heat, and road debris, offering superior durability compared to traditional rubber bushings. This longevity ensures that the performance benefits are maintained over time.

  3. Improved Driver Feedback: By minimizing movement in the rear differential, these bushings enhance the connection between the vehicle and the driver. This results in better feedback and control, allowing for a more engaging driving experience.

  4. Direct Fit for Easy Installation: Designed specifically for the E39 5 Series, these bushings fit directly into the existing differential mounts, facilitating a hassle-free installation process without the need for modifications.

This upgrade is perfect for BMW E39 5 Series enthusiasts who want to improve their vehicle's handling and performance, making it suitable for both daily driving and spirited performance applications. The Powerflex Rear Differential Rear Mount Bushings provide a reliable solution to enhance the overall effectiveness of the rear suspension system.

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OS Giken - Corporate Logo
T#:34382136
Part#: BM237HAKT
Ships in 2 Business Days
$ 2,100.00 USD
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Upgrade to a better performing LSD, includes tune.
Condor Speed Shop - Corporate Logo
T#:597363
Part#: TRANSIX_E39P
Ships in 2 Business Days
$ 35.00 USD
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The 70A poly mounts are the solution if you are trying to minimize vibration and NVH. They are currently the softest polyurethane mounts on the market. We suggest these for all street cars. If you are building a track car, check out the solid UHMW transmission mounts from Condor Speed Shop.
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Team MFactory - Corporate Logo
T#:379403
Part#: MF-TRS-05E39
Back Ordered
$ 999.99 USD
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$ 999.99 USD
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Allows for traction at all times by providing the most power to the wheel with more grip. Unlike plate differentials (1,1.5,2-way) helical LSDs can supply different spin rates to each axle, like when cornering.
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OS Giken - Corporate Logo
T#:34382134
Part#: LSD-TUNE
Ships in 2 Business Days
$ 150.00 USD
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$ 150.00 USD
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