BMW Differential and Gearing Upgrades for BMW G82 M4 S58 3.0L

Harness unused potential. Drive with confidence. Engineered to maximize strength and cooling performance while utilizing the unused secondary factory differential mount for enhanced support and driveline stability.

Our Turner Motorsport Dual-Mount Differential Cover is purpose-built to reinforce one of the most critical components in the G8X M3/M4 drivetrain. From the factory, BMW includes a secondary bushing location in the rear subframe but leaves it unused. Our solution fully capitalizes on this overlooked feature, giving the differential a second point of support for improved rigidity, reduced movement, and enhanced driveline response under load.

This cover is more than just a mounting upgrade. It’s precision-machined from 6061-T6 billet aluminum for exceptional strength without unnecessary weight. An aggressive fin profile improves thermal efficiency, helping to lower fluid temperatures in high-stress environments. Inside, the cover features an embossed channel that mirrors the ring gear path, ensuring fluid stays in contact where it's needed most, improving cooling and lubrication in all conditions.

Whether you're carving corners on the street or pushing the limits on track, this differential cover is designed to keep your rear end cool, stable, and responsive.

Key Features and Benefits:

The dual-mount design utilizes the factory-provided secondary bushing location, adding critical support to reduce differential deflection, extend bushing life, and minimize wheel hop.
CNC-machined from 6061-T6 billet aluminum, offering high strength and a precise fit.
Built-in cooling fins increase surface area for improved heat dissipation and lower differential fluid temperatures.
Internally contoured to follow the ring gear profile, promoting consistent fluid coverage and effective lubrication.
Maintains a 1.1-liter fluid capacity, closely matching OEM specifications for ease of servicing.
Integrated -6 AN ports support the addition of an external differential cooler for increased fluid volume and extended service intervals.
Compatible with the factory differential fluid temperature sensor and includes provisions for 1/4” NPT aftermarket sensors.
Product Development:

Like all Turner Motorsport performance solutions, this differential cover was developed in-house by our dedicated Research and Development team. Designed, engineered, tested, and quality-inspected using advanced tools including FARO laser scanning for reverse engineering, SolidWorks 3D CAD modeling, in-house rapid prototyping, and extensive long-term testing, you can trust that this part meets the highest standards of fit, function, and durability.

From spirited street driving to full-throttle track days, the Turner Motorsport Dual-Mount Differential Cover ensures your G8X delivers the response, strength, and cooling capacity it needs when it matters most.

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.