Two Years of Engineering, Nürburgring Tested, Built for the G8X Platform
When pushing the G87 M2, G80 or G81 M3, or G82 or G83 M4 beyond factory limits, the differential becomes one of the weakest parts of the drivetrain. The G8X rear end generates significant heat and oil turbulence during high load driving, which often leads to inconsistent lubrication, increased drivetrain losses, and premature performance limitations. After more than two years of development and validation, including testing at the Nürburgring, MMX created a solution that addresses these issues in a way that feels factory engineered.
The MMX High Capacity Baffled Differential Sump is designed to keep the G8X differential cooler, better lubricated, and more stable when used on track or in demanding street applications. Every element of the design serves a clear purpose. This is not a cosmetic part or a simple capacity increase. It is a functional upgrade for enthusiasts who want reliability, consistency, and performance at the limit.
More Oil Capacity, More Stability, More Confidence
The G8X differential struggles with oil starvation under heavy cornering loads. During sustained lateral G, the factory sump allows oil to pull away from the pinion and gearset. This leads to heat spikes, drivetrain drag, and ultimately the common “Rear Axle Differential Lock: Driving Stability Limited” warning that forces many drivers to end their sessions early.
The MMX differential sump increases oil capacity by up to 2 liters. The additional volume delivers a larger and more stable lubrication supply, even during repeated high load transitions. Combined with the integrated billet windage tray, the system ensures constant oil delivery to the gearset and pinion while reducing internal drag. The benefit is simple. Cooler operation, more consistency, and significant reduction in oil foaming at aggressive driving angles.
Engineered Cooling from the Inside Out
Heat is a constant enemy in differential performance. MMX addressed it from both sides. The sump features internal and external cooling fins that dramatically increase surface area. The design extracts heat from the housing efficiently and allows the oil to return to working temperature faster.
This stability in temperature is what separates casual spirited driving from real motorsport use. Extended sessions at a track day or endurance event require thermal consistency. The MMX sump manages heat in a way the OEM part cannot.
CNC Billet Construction with True OE Integration
Each unit is CNC machined from 6061-T6 billet aluminum and designed with long-term durability in mind. Every pocket and surface has a purpose. There is no unnecessary weight, and no compromise in sealing, rigidity, or fitment.
Installation is direct. No cutting and no modification. The sump mounts to the factory locations and integrates with the G8X drivetrain exactly as a production-level part should.
For drivers who want additional rigidity, the sump is fully compatible with the MMX Dual Differential Mount. The system can be used independently or paired for maximum stability under load.
Eliminates the Most Common Track Issue
The MMX sump helps prevent the widely reported “Rear Axle Differential Lock: Driving Stability Limited” warning that plagues G8X owners who push their cars on track. Instead of relying on software resets or cooling margins that diminish performance, this system addresses the mechanical root of the problem. More lubrication, better flow, and reliable thermal control.
Future-Proofed for External Cooling
For customers running extremely high temps or competition setups, the sump includes an additional -8AN port and an M22 to -8AN adaptor. Integrating an external differential cooler becomes a clean and straightforward process.
Fitment
- BMW G87 M2
- BMW G80 or G81 M3
- BMW G82 or G83 M4
- Compatible with both RWD and xDrive
What is Included
- CNC machined high capacity baffled sump
- CNC machined windage tray
- Magnetic drain plug with seal
- Fill plug with seal
- M22 to -8AN adaptor for external cooler
- Complete installation hardware
Key Advantages
- Up to 2 liters of increased differential oil capacity
- Integrated windage tray for constant lubrication and reduced drag
- Reduced drivetrain losses and extended component life
- Internal and external fins for superior heat management
- CNC machined 6061-T6 billet aluminum
- Direct OE style fit without modification
- Compatible with MMX Dual Differential Mount
- -8AN port for external cooler integration
- Helps prevent Driving Stability Limited warnings
- Ideal for track use, endurance sessions, and high performance builds
For G8X drivers who want real performance instead of temporary solutions, this differential upgrade delivers engineering, testing, and reliability that meets the demands of modern motorsport. If you want pricing, installation support, or combined packages with the MMX dual mount, contact our team.
