BMW F2x F3x Billet Differential Insert Kit - Rear Diff Mount Bush Upgrade
Designed and engineered in-house in the UK, this precision machined billet aluminium differential insert kit for BMW F2x and F3x platforms is the essential rear diff mount upgrade for sharper handling, improved traction and a more connected drive. By filling the small voids in the four factory rubber diff mounts and limiting vertical movement, these inserts reduce differential movement under acceleration, gear shifts and deceleration to keep suspension geometry correct when cornering and to tighten up rear end response.
If you want a BMW diff insert upgrade that improves stability without ruining comfort, this is it. Expect reduced driveline slop, more immediate throttle response and a planted, confidence inspiring rear axle on fast road and track, all while maintaining excellent refinement for daily driving.
Why upgrade the BMW F2x F3x differential bushes
The OEM rubber differential mounts on BMW F2x and F3x cars deflect under load which makes the rear end feel vague and loose, shifts suspension geometry off target and can contribute to increased understeer. These billet inserts eliminate that unwanted movement and associated slop so you experience crisper turn in, better mid corner stability and cleaner power delivery on corner exit. They also enhance the effectiveness of aftermarket rear anti roll bars and performance suspension components.
Low NVH with daily friendly comfort
Worried about noise, vibration and harshness. Based on feedback, these 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 experience higher than quoted NVH, please evaluate the installation to ensure the components are installed correctly.
Fast, reversible installation
Installation is simple, can be performed in under an hour, is completely reversible and the differential remains in situ. No pressing out bushes and no permanent modifications. A smart, bolt in BMW rear diff bushing insert solution that delivers real performance.
Features
- 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 bush voids to minimise component movement
- Simple installation with differential remaining in situ
- Helps maintain correct suspension geometry under dynamic loading
Tested on UK roads and track
These inserts were tested extensively by MMR and independent BMW enthusiasts on multiple F2x and F3x vehicles. They fit diesel and petrol models, manual and automatic variants. We have installed these on customer BMW 1 Series, 2 Series, 3 Series and 4 Series builds and feedback has been excellent, with noticeably tighter rear end control and minimal change in cabin refinement.
Fitment and search friendly compatibility
Compatible with BMW F2x and F3x chassis including BMW 1 Series, 2 Series, 3 Series and 4 Series. Ideal for popular models such as BMW M135i, M140i, M235i, M240i, 335i, 340i, 435i, 440i as well as diesel variants like 320d, 330d and 435d. Perfect BMW differential insert upgrade, BMW rear diff bush insert, BMW F20 F21 F22 F23 F30 F31 F32 F33 F36 diff mount upgrade for road and track performance.
Professional fitting
Want it fitted. Nforcd offers professional installation in Warwickshire. Request a fitting quote at Sales@nforcd.com.
Order now for a proven BMW F2x F3x differential insert kit that improves handling, enhances traction and sharpens response while keeping NVH in check.