Drivetrain Mounts and Upgrades

Upgrade your drivetrain performance with ECS Tuning Performance Polyurethane Differential Bushings—engineered specifically for BMW F8x/G8x models and designed to deliver superior power transfer, durability, and driving precision.

Factory rubber differential bushings are built for comfort, absorbing vibrations between the differential and chassis during everyday driving. However, they are a known wear item that degrade over time—especially under spirited or aggressive driving conditions. Many F8x/G8x owners experience premature cracking and wear, leading to excessive drivetrain movement, reduced throttle response, and unwanted wheel hop.

ECS Tuning’s in-house engineered polyurethane differential bushings provide a high-performance solution to these common issues. By significantly reducing drivetrain deflection, these upgraded bushings enhance throttle response, improve handling stability, and minimize wheel hop—resulting in a more connected and controlled driving experience.

Constructed from durable 95A durometer red polyurethane and paired with precision CNC-machined 6061-T6 aluminum sleeves, these bushings are built to withstand extreme driveline forces while maintaining street-friendly comfort. Unlike solid or delrin mounts, ECS polyurethane bushings strike the perfect balance between performance and daily drivability—delivering increased rigidity without excessive noise, vibration, or harshness (NVH).

Whether you're carving canyon roads, launching at the drag strip, or simply commuting, these performance differential bushings ensure more efficient power delivery from the differential to the wheels—giving you better throttle modulation, traction, and overall control.

Key Features & Benefits:

Performance polyurethane differential bushings for BMW F8X models
Reduces drivetrain movement and improves power transfer
Enhances throttle response and minimizes wheel hop
95A durometer polyurethane for optimal balance of performance and comfort
CNC-machined 6061-T6 aluminum inserts with Type II black anodizing for corrosion resistance
Resistant to oil, chemicals, ozone, and road salt for extended service life
Designed to handle high torque loads and extreme driving conditions
Engineered using real-world load data and worst-case operating scenarios
Maintains street-friendly NVH levels compared to solid mounts
Replace worn factory bushings with ECS Performance Polyurethane Differential Bushings and experience tighter handling, improved drivetrain response, and long-lasting reliability.

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.

Don't neglect your motor mounts! Most stock BMW motor mounts are fluid filled and the stiffness of the mount depends on this fluid. But over time the fluid leaks out and the strength of the mount is greatly reduced. A worn motor mount allows the engine to twist and shift around. The harder you're driving the more shift will occur. As the engine is moving around it can contact other parts in the engine bay - usually cooling related. The mechanical fan can hit the radiator; the A/C compressor can hit a radiator hose, the exhaust will flex and may break. Twisting of the engine can also lead to shifting problems as the transmission twists with it. There are countless issues related to worn or compressed motor mounts so don't overlook these as a regular replacement item (every 50,000 miles).

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:
E46 Non-M
E85 Z4 2.5i/3.0i/3.0si
E89 Z4 3.0si

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 street bushings are ideal for street driven vehicles and those that see occasional autocross or track time. Need bushings for a dedicated track car? 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 steering feel, turn in, more responsive handling and overall improved chassis composure with Powerflex performance polyurethane control arm 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. 

BMW E9X 335i BMS Differential Support Bracket Brace - Small Case

The BMW E9X 335i BMS Differential Support Bracket Brace - Small Case is a high-performance upgrade designed to enhance the stability and durability of the differential mount. Turner Motorsport offers this precision-engineered brace to reduce flex and movement of the differential, ensuring improved power transfer and handling. Ideal for high-performance driving or track use, this brace helps maintain proper alignment and extends the lifespan of your differential components.

Benefits:

• Enhances differential stability by reducing flex and movement
• Improves power transfer and handling performance
• Precision-engineered for a perfect fit and reliable performance
• Ideal for high-performance driving and track use
• Extends the lifespan of differential components
• Made from high-quality materials for durability and strength