BMW F-Series

BMW F-Series Limited Slip Upgrade – Complete Built Rear Final Drive, 2.81 Ratio, 215K Housing

Transform how your BMW puts power to the ground with this fully assembled rear differential featuring a Wavetrac helical limited slip centre and a 2.81 ring and pinion in the 215K case. This bolt-in rear axle assembly is a proven traction upgrade for fast-road driving and track days, delivering sharper exits, stronger acceleration out of bends and impressive stability in tricky conditions.

Compatible applications include selected F-Chassis models such as M140i, M240i, 325d, 340i and 340i xDrive that utilise the 215K final drive with a 2.81 ratio. If you would like us to confirm fitment for your VIN, just get in touch.

Why this differential upgrade stands out

• Maintains drive even when one wheel goes light over kerbs or on slippery surfaces. The Wavetrac internal wave-cam mechanism generates the load needed so the wheel with grip keeps receiving torque, giving more consistent push off the apex and improved corner exit speed.
• Carbon fibre thrust plates keep performance consistent over time. Unlike typical helical centres that rely on housing friction that changes with wear, Wavetrac’s design delivers repeatable behaviour mile after mile.
• Refined on-road manners with strong on-track performance. Enjoy confident traction without the binding, noise or understeer traits associated with clutch-pack units.
• Works seamlessly with factory stability and traction systems during normal driving. Ideal for daily use and weekend blasts.
• Built to last with high-tensile ARP fasteners and a premium 9310 alloy gearset housed in robust steel casings. Engineered and manufactured in the USA.

Real-world benefits you will feel

• Stronger traction off the line and out of slow corners
• Predictable, smooth power delivery near the limit
• Confident performance in wet, cold or greasy conditions
• Faster, more stable corner exits on track days
• Quiet, low-maintenance operation with no clutch packs to service

What you are getting

A pre-built rear final drive assembly using the 215K casing with a 2.81 ratio and a Wavetrac helical limited slip centre installed. A true plug-in performance differential upgrade for suitable BMW F-Series models seeking a serious traction improvement.

Fitment highlights and search-friendly terms

Ideal search terms customers use for this unit: BMW F-Series limited slip, F20 F21 diff upgrade, M140i rear diff, F22 F23 performance differential, M240i LSD conversion, F30 325d rear axle, F30 340i differential ratio 2.81, 340i xDrive rear end, helical LSD for BMW, 215K pumpkin, complete final drive assembly.

Why buy from us

We run these units ourselves and our customers consistently report transformative traction, smoother cornering and greater confidence in all weather. It is one of the most effective drivetrain upgrades you can make to a BMW F-Series performance model.

Professional installation

Want it fitted properly first time. Book expert installation with MJ Modifications in Warwickshire. Email info@mjmodifications.co.uk for a fitting quote and availability.

Note: Please confirm your car’s differential housing and ratio before ordering to ensure compatibility with the 215K 2.81 final drive specification.