BMW F Series Rear Diff Upgrade - M Performance Limited-Slip (LSD) / Locking Final Drive 33108659989 for RWD Auto F20 F21 F22 F23 F30 F31 F32 F33 F36 - Fits M140i M

BMW F Series Rear Axle Performance Differential Upgrade - Part No. 33108659989

Transform the way your BMW puts power to the tarmac with the factory-engineered locking rear differential, part number 33108659989. This OE rear final drive is designed for rear wheel drive automatic F Series models and delivers serious traction, cleaner corner exit and a huge boost in driver confidence. It is the go-to drivetrain upgrade for fast road use and track days if you want real mechanical grip without compromising refinement.

• Authentic BMW performance rear end assembly for F Series platforms
• Massive improvement in drive out of bends and on low-grip surfaces
• OE quality and durability with BMW-developed locking characteristics
• Direct swap for the standard open differential, keep your original unit for resale or revert
• Proven on customer cars and our own builds - the difference in stability and traction is immediate

What you will feel

More drive to both rear wheels when one starts to unload, calmer behaviour on throttle, and noticeably faster corner exits. The mechanical locking action biases torque across the rear axle without relying on brake intervention, giving you predictable, progressive traction that inspires confidence on wet roads, dry roads and circuits alike. Expect better balance in tight hairpins, smoother power delivery mid-corner and more control when accelerating over cambers or uneven surfaces.

Fitment - rear wheel drive automatic only

• BMW 1 Series - F20 F21 - M140i - automatic transmission
• BMW 2 Series - F22 F23 - M240i - automatic transmission
• BMW 3 Series - F30 F31 - 340i - automatic transmission
• BMW 4 Series - F32 F33 F36 - 440i - automatic transmission

Not suitable for xDrive all-wheel drive cars or manual gearbox variants.

Why choose this upgrade

• Real mechanical traction for B58-powered F Series performance models
• Improves cornering stability, turn-in confidence and exit speed
• Ideal for spirited driving, time attack and track day use
• Engineered by BMW for consistent locking behaviour under acceleration and deceleration
• Self-contained assembly makes installation straightforward for a BMW specialist

Genuine OE part and support

This is an original BMW performance rear differential assembly, part number 33108659989. Manufacturer warranty applies when supplied for a compatible vehicle. UK customers benefit from two years warranty, international customers one year, when a valid VIN is provided at checkout.

Professional installation

We recommend expert fitting. MJ Modifications offers installation at our Warwickshire workshop. Request a tailored quote and availability via info@mjmodifications.co.uk.

Fluids

If a top-up is required after installation, use Genuine BMW M Performance LSD oil as specified by BMW.

Pre-dispatch compatibility check

We verify fitment before shipping. Add your UK registration or the last 7 of your VIN at checkout so our team can confirm suitability for your specific F Series BMW.

Part number

33108659989

Search terms to help you find this upgrade

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