ECS BMW Differential and Gearing Upgrades for BMW X Series E83 (2004-2010)

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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 Magnetic Differential Oil Drain Plug - Most BMW & Mini Models ...
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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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E46 non-M Performance Polyurethane Differential Bushing Set
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T#:378192
Part#: 002447ECS02KT
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Sale - Save 25% $ 183.99

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06-13-2026

$ 137.99 USD
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Sale - Save 25%
$ 183.99

This product was last offered at the strikethrough price on
06-13-2026

$ 137.99 USD
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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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BMW E46 Z4 Rear Polyurethane Differential Bushing Performance ...
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T#:363117
Part#: 002447ECS03
In Stock
Sale - Save 25% $ 88.99

This product was last offered at the strikethrough price on
06-13-2026

$ 66.74 USD
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Sale - Save 25%
$ 88.99

This product was last offered at the strikethrough price on
06-13-2026

$ 66.74 USD
Free Shipping on orders $49 and up

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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