The factory rear differential bushing in an M2, M3 or M4 is soft rubber, and it lets the differential shift every time you put power down. The MMX Performance Rear Differential Polyurethane Bushing swaps it for 80A durometer polyurethane with a black anodized 6061-T6 aluminum sleeve, giving you a tighter, more controlled connection between the differential and the chassis.
One part number fits both generations: the F87 M2, F80 M3 and F82 / F83 M4, and the G87 M2, G80 / G81 M3 and G82 / G83 M4. It drops into the factory location with no cutting or drilling, and the increase in NVH is minimal, so it works on a daily driver as well as a track car.
Rear Differential Polyurethane Bushing Setups
Single bushing: use one as a direct replacement for the factory rear differential bushing. It keeps the standard differential mounting height.
Two bushings with a dual mount: an MMX Dual Differential Mount adds a second rear mounting point, and each point takes one of these bushings, so you need two. The dual mount is chassis-specific: F8X cars use the MMX F8X Dual Differential Mount (MMR55-1001) and G8X cars use the MMX G8X Dual Differential Mount (MMR55-1606). This bushing fits both.
Need the +10mm raised differential height on a lowered G8X? That uses the MMX raised rear differential bush (MMR55-1605) instead.
What's Included
- 1 x MMX rear differential polyurethane bushing (sold individually)
Key Features
- Direct replacement for the factory rear differential mounting bushing
- 80A durometer grey polyurethane
- Black anodized 6061-T6 aluminum sleeve
- Reduces differential and drivetrain movement under load
- No cutting, drilling or permanent modification
- Minimal increase in NVH
- Retains the standard differential mounting height
- Fits F8X and G8X M2 / M3 / M4
- Part number: MMR55-1603
Vehicle Fitment
Fits the following models:
- BMW G80 M3 Sedan (2021-2026)
- BMW G82 M4 Coupe (2021-2026)
- BMW G83 M4 Convertible (2022-2026)
- BMW G87 M2 (2023-2026)
- BMW G81 M3 Touring (2023-2026, not sold in the US)
- BMW F80 M3 Sedan (2015-2018)
- BMW F82 M4 Coupe (2015-2020)
- BMW F83 M4 Convertible (2015-2020)
- BMW F87 M2 (2016-2018)
- BMW F87 M2 Competition (2019-2021)
Installation Notes
Professional installation is recommended. Order two bushings if you are running an MMX Dual Differential Mount.
- Raise the car and support the rear differential.
- Remove the factory rear differential mount bushing.
- Press in the MMX polyurethane bushing at the factory location.
- Refit the differential and torque the hardware to BMW specification.
