BMW Differential and Gearing Upgrades for BMW Z Series E85/6 (2003-2008)

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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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ECS - Corporate Logo
T#:366828
Part#: 009314ECS01A
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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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Loctite - Corporate Logo
T#:25772539
Part#: 5970
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This Loctite 5970 Sealant is recommended by BMW to be used to seal the rear differential cover and numerous engine oil pans. Also used for multiple MINI, Audi, and VW applications.
ECS - Corporate Logo
T#:378193
Part#: 002447ECS03KT
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Worn rubber differential mounts will lead to the differential twisting and shifting around in the rear subframe. Not only will this be noisy but it's bad for driver confidence and bad for the chassis as well. Even on fresh rubber bushings the differential has deflection and twist, especially if the car has been modified for more torque. Since the differential is centrally mounted in the rear subframe, with all suspension mounts interconnected, a differential with too much deflection will affect handling and could even damage the rear subframe.

These 88A urethane E46 M3 diff mounts are much stiffer than stock but still not as solid as our Turner aluminum/Delrin bushings. This set will resist twisting much better than the stock rubber mounts. Included is the front diff mount and two rear mounts in the cover.

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ECS - Corporate Logo
T#:348998
Part#: 002447ECS01
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This product was last offered at the strikethrough price on
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$ 148.99

This product was last offered at the strikethrough price on
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$ 111.74 USD
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Revitalize your driving experience with ECS Tuning's In-House Engineered Performance Polyurethane Differential Bushings. Say goodbye to soft factory rubber bushings and their deflection. These innovative bushings provide a substantial improvement in the connection between your right foot, the chassis, and the wheels. The outcome is a crisper power transfer from the differential to the wheels, resulting in enhanced throttle control for various driving activities. Notably, these polyurethane bushings achieve these benefits without the harshness or vibration often linked to delrin or solid differential mounts.

Manufactured using a robust 88A durometer polyurethane and a black anodized 6061-T6 aluminum sleeve, these bushings offer superior resistance to chemicals, ozone degradation, road salt, and general wear and tear. This translates to an extended service life.

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ECS - Corporate Logo
T#:378192
Part#: 002447ECS02KT
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This product was last offered at the strikethrough price on
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Worn rubber differential mounts will lead to the differential twisting and shifting around in the rear subframe. Not only will this be noisy but it's bad for driver confidence and bad for the chassis as well. Even on fresh rubber bushings the differential has deflection and twist, especially if the car has been modified for more torque. Since the differential is centrally mounted in the rear subframe, with all suspension mounts interconnected, a differential with too much deflection will affect handling and could even damage the rear subframe.

These 88A urethane E46 diff mounts are much stiffer than stock but still not as solid as our Turner aluminum/Delrin bushings. This set will resist twisting much better than the stock rubber mounts. Included are the two front diff mounts and the rear mount in the cover.

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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
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Sale - Save 25%
$ 42.99

This product was last offered at the strikethrough price on
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$ 32.24 USD
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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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ECS - Corporate Logo
T#:363117
Part#: 002447ECS03
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BMW E46 Z4 Rear Polyurethane Differential Bushing Performance is the ultimate upgrade for enhancing the connection between your BMW's chassis and differential. Designed by Turner Motorsport, this performance bushing replaces the soft factory rubber with durable polyurethane, offering superior control and response. By minimizing vibrations and reducing deflection, this bushing ensures a more direct and responsive driving experience, making it a must-have for any performance-oriented BMW E46 or Z4 owner.

  • Enhanced Performance: Replaces the soft factory rubber with durable polyurethane for improved driveline response.
  • Reduced Vibrations: Minimizes vibrations between the chassis and differential, providing a more connected driving experience.
  • Increased Durability: Made from high-quality polyurethane, offering long-lasting performance under demanding conditions.
  • Improved Control: Reduces deflection, ensuring a more precise and responsive handling experience.
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ECS - Corporate Logo
T#:378219
Part#: 002447ECS04KT
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Sale - Save 25% $ 112.99

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$ 84.74 USD
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Sale - Save 25%
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This product was last offered at the strikethrough price on
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$ 84.74 USD
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Your rear differential is indirectly connected to your right foot through the engine and driveline, and connected to the seat of your pants through the chassis. Soft factory rubber differential bushings absorb vibrations between chassis and differential, providing comfort and softness in both of these connections.

Enter ECS Tuning's In-House Engineered Performance Polyurethane Differential Bushings. By eliminating the deflection factory rubber bushings permit, the connection between your right foot (and your seat) to the wheels is improved. Removal of this slop allows for crisper power transfer from differential to wheels, which means better throttle control while carving a canyon road, drag racing, sliding the rear end out, or just driving to work. This is achieved without the harshness or vibration associated with delrin or solid differential mounts.

Featuring a tough 88A durometer polyurethane and Black anodized 6061-T6 aluminum Sleeve, our Performance Polyurethane Differential Bushings are more resistant to chemicals, ozone degradation, road salt, and general wear and tear than factory rubber bushings, resulting in a longer service life.

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OEM Lemforder Differential Rubber Mounting Rear - 33173449082 - E83,E...
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Lemforder - Corporate Logo
T#:398994
Part#: 33173449082
Special Order: No Guaranteed ETA
$ 27.99 USD
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Bushings tends to wear over time and split or even break free from the internal sleeve, causing excessive movement and sloppy control feel. OEM Lemförder bushings are the perfect option to restore suspension back to day 1 quality.

OEM Lemförder is an engineering company that focuses on high-quality, precision manufacturing of critical suspension and steering components. Providing exceptionally high quality parts directly to BMW, as well as 50+ other big name automotive companies, such as Mercedes and Audi, their history of reliability and variety of offered parts makes them one of the biggest names for a go-to OEM parts provider. Lemförder parts place an important emphasis on design, production, and assembly, ensuring maximum reliability. They even coat all parts possible with corrosion protection for extended longevity.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMW Chassis:
E83 X3,E85,E86,E89 Z4

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Rear Axle Rubber Mounting FRONT 33176770788
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Lemforder - Corporate Logo
T#:15674
Part#: 33176770788
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$ 17.99

This product was last offered at the strikethrough price on
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$ 12.50 USD
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RUBBER MOUNTING FRONT