Drivetrain Mounts and Upgrades for BMW G80 M3 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.

Enhance rear-end control and put more power to the ground with a straightforward 3-piece design that installs with ease. The factory rubber may favor ride comfort, but it struggles to keep up when driving gets aggressive. As it wears, the OEM bushing can soften and deform, reducing stability and allowing wheel hop to creep in when you need traction most.

Our 95A durometer polyurethane bushings solve that problem. Engineered to strike the perfect balance between soft factory rubber and harsh solid mounts, they significantly reduce differential movement without introducing excessive vibration. The result is more efficient power transfer, so your torque goes straight to the rear wheels instead of being lost in drivetrain flex.

Features & Benefits:

Minimizes differential movement and instability to help eliminate wheel hop
Two-piece 95A split polyurethane design for easier installation
Precision-fit insert reinforces the bushing and strengthens mounting points
Resistant to road salt, oils, and harsh chemicals
Compatible with dual mount differential plates
Design:

Type II Anodized 6061-T6 CNC billet aluminum inserts for superior corrosion resistance and durability.
95A Polyurethane 2-Piece Isolator.
Product Development:

Our Rear Differential Bushings are designed, engineered, tested, and quality inspected by our Research & Development team. Our development process includes leading-edge product technology: FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.