A hard track session pushes the G8X rear differential oil temperature up fast, and hot oil is thin oil. The MMX Performance High-Capacity Baffled Differential Sump adds up to 2 liters of capacity, cools that oil through internal and external fins and keeps it at the gears under load.
It is a direct OE-style replacement for the factory rear diff pan, for RWD and xDrive cars.
How the G8X Baffled Differential Sump Works
Machined from billet aluminum, the sump carries an internal baffled windage tray that stops oil sloshing away from the gears in long corners. A dedicated port, with adaptor included, lets you add an external diff cooler later. It works with the MMX 3-Point Differential Lift Kit and the MMX dual differential mount.
What's Included
- 1 x MMX billet high-capacity differential sump
- 1 x internal baffled windage tray
- Drain and fill plugs with seals
- External cooler adaptor
- Mounting hardware
- BMW RTV sealant (83190404517) with the RTV option
Key Features
- Up to 2 liters of additional differential oil capacity
- Internal baffled windage tray controls oil movement
- Internal and external cooling fins
- Port and adaptor for an external diff cooler
- CNC-machined billet aluminum, direct OE-style fit
- RWD and xDrive compatible
- 1-year MMX warranty against defects in materials and workmanship
- Part numbers: MMR55-1600, MMR55-1600-RTV (with BMW RTV sealant)
Vehicle Fitment
Fits the following models, RWD and xDrive:
- BMW G80 M3 Sedan (2021-2026)
- BMW G82 M4 Coupe (2021-2026)
- BMW G83 M4 Convertible (2022-2026)
- BMW G87 M2 (2023-2026)
F97 X3M and F98 X4M fitment is not confirmed.
Installation Notes
Professional installation is recommended. The factory pan seals with RTV, so choose the RTV option if you do not have BMW sealant on hand.
- Drain the differential oil and remove the factory sump.
- Clean the mating surface thoroughly.
- Apply BMW RTV and install the MMX sump with the windage tray.
- Allow the sealant to cure, then refill with the added capacity and check for leaks.
