Skip to product information
1 of 5

MMR Performance



Regular price £119.99 GBP
Regular price Sale price £119.99 GBP
Sale Sold out
Tax included. Shipping calculated at checkout.
Designed and engineered in-house in the UK, the MMR differential insert kit for the BMW F2x and F3x chassis is designed to limit movement in the factory diff mounts to maintain proper suspension geometry when cornering and improve the responsiveness of the rear suspension and diff. Installation is very simple, can be performed in under an hour, and is completely reversible.

By filling small voids in the four factory mounts as well as limiting vertical movement, the insert set eliminates the associated slop to ensure that you experience a more refined, connected driving experience, especially when driving at the limit. The billet aluminium parts will not wear over time and offer a lasting performance improvement.

Worried about noise? NVH is a measurement of how much noise, vibration, & harshness gets transmitted into a vehicle’s cabin. Based on feedback, MMR inserts transfer little to none NVH into the cabin. NVH is subjective, so some users may find NVH to be increased or decreased from our rating. If you are experiencing higher than quoted NVH with this product, please evaluate the installation to ensure the components are installed correctly.

The BMW F2x and F3x series use rubber diff mounts that deflect under load, causing the rear end to feel vague and loose, as well as leading to less-than-optimal suspension geometry and increased understeer. These precision-machined billet aluminium inserts are designed to fill voids in the factory diff mounts, and limit diff movement without sacrificing ride quality or introducing any perceivable additional noise, vibration, or harshness into the cabin. The result is a more refined, connected driving experience, as well as improved effectiveness of aftermarket rear sway bar upgrades and suspension components.

These inserts were tested extensively by MMR and independent BMW enthusiasts before release on multiple F2x and F3x vehicles. Our diff inserts fit diesel, petrol, manual and auto variants.


  • Black Anodised 6061-T6 Billet Aluminium with stainless setter retaining
  • Designed to reduce differential movement while keeping NVH to a minimum
  • Reduces differential movement under acceleration, gear shift and deceleration
  •  Fills OE bushes voids to minimise component movement  
  • Simple installation with differential remaining in situ
  • Helps maintain correct suspension geometry under dynamic loading
View full details