MMX BMW F2X/F3X Billet Aluminium Rear Differential Insert Kit Diff Mount Bush Upgrade for 1/2/3/4 Series (F20 F21 F22 F23 F30 F31 F32 F33 F36)

BMW F20 F21 F22 F23 F30 F31 F32 F33 F36 Rear Final Drive Mount Insert Set

Sharpen your BMW’s rear end response with this CNC machined alloy insert set for the rear final drive mounts. By occupying the voids in the factory rubber bushes, these inserts control unwanted movement in the drivetrain under acceleration, gearchanges and lift off. The result is tighter chassis feel, cleaner power delivery and a more planted rear axle on fast road and track day use without sacrificing daily comfort.

Precision crafted from 6061-T6 aluminium and black anodised for durability, this complete kit supports all four bush locations on the differential carrier. Expect reduced driveline slack, improved throttle response and more consistent traction on corner exit. Our workshop has installed these on multiple customer 1 Series, 2 Series, 3 Series and 4 Series builds with excellent feedback and zero fuss fitting.

Key benefits

• Controls rear final drive movement for crisper handling and better traction
• Helps mitigate wheel hop and axle tramp on hard launches
• Keeps rear suspension geometry stable during load transfer
• Transforms rear end precision with minimal increase in cabin NVH
• Machined 6061-T6 alloy inserts with corrosion resistant anodised finish
• Reversible install with the differential left in place

How it improves your BMW

The standard rubber mounts allow the final drive casing to shift vertically and fore aft when you put torque through the drivetrain. These inserts support the OEM bushes, cutting compliance that makes the back end feel loose. You get cleaner shifts, more immediate power application, better mid corner stability and confidence inspiring grip. A perfect pairing with performance springs, dampers and rear anti roll bars.

Comfort and NVH

Real world testing on UK roads shows only a subtle change in cabin noise and vibration. Most drivers report a more solid, quality feel with negligible harshness. As with any chassis upgrade, correct installation is essential to achieve the intended refinement.

Installation

Straightforward bolt in fitment with no pressing out of factory bushes and no permanent modification. The differential stays in situ which keeps labour time sensible and makes the upgrade fully reversible should you ever return to stock.

Compatibility

For BMW F2x and F3x platforms including:

• 1 Series F20 F21
• 2 Series F22 F23
• 3 Series F30 F31
• 4 Series F32 F33 F36

Suits popular petrol and diesel models such as M135i, M140i, M235i, M240i, 335i, 340i, 435i, 440i, 320d, 330d, 435d. Compatible with rear wheel drive and xDrive, manual and automatic transmissions including ZF8. Ideal search terms include BMW rear diff bushing inserts, final drive mount inserts, BMW drivetrain bush upgrade, F20 F21 F22 F23 F30 F31 F32 F33 F36 diff inserts, BMW wheel hop fix and BMW F series handling upgrade.

Why buy from us

We have fitted this kit many times in house and customers consistently praise the improved rear end control and traction. It is a high value handling upgrade that complements Stage 1 and Stage 2 power levels and stands up to daily driving and track sessions alike.

Professional fitting

Want it installed by experts. MJ Modifications in Warwickshire offers professional fitting. Request a quote at info@mjmodifications.co.uk.

Upgrade your F series BMW with a robust rear final drive mount insert kit that tightens the chassis, boosts confidence and keeps refinement intact. In stock and ready to transform your drive.