BMW M140i M240i B58 RWD Limited Slip Differential - Quaife ATB Helical LSD Rear Diff/Final Drive Assembly/Axle in Casing, Plug & Play Bolt-In Pumpkin Swap, Complete Drop-In Carrier, F20 F21 F22 F23 1 Series 2 Series, Exchange or No Exchange

Direct-fit Rear Final Drive with Quaife ATB for BMW M140i and M240i B58 RWD

Unlock the traction your B58-powered 1 Series or 2 Series deserves with this pre-built rear axle assembly featuring the renowned Quaife ATB torque-biasing centre. Supplied as a complete, bolt-in carrier in its casing, it is a true plug and play upgrade that delivers stronger drive out of bends, cleaner launches and confidence in all weather. UK engineered, quiet in use and maintenance free with Quaife’s lifetime warranty.

• Complete rear final drive in casing – pre-built, shimmed and ready to install
• Helical gear, torque-biasing unit that reduces inside wheel spin and maximises grip
• No clutch packs to wear, no servicing, consistent performance on road and track
• Works seamlessly with factory electronics including DSC, ABS and traction control
• Ideal for tuned B58 cars and spirited fast-road driving, track days and drag starts
• UK quality with lifetime warranty from Quaife for long-term peace of mind

What is included

A fully assembled rear diff housing with the Quaife ATB installed, set up and ready to go. No pressing of gears or backlash setup required. This product is offered on an exchange basis. If you cannot provide a suitable core, select the no exchange option before checkout. For higher mileage vehicles or big power builds we recommend the high performance bearings option.

Why this upgrade works

The Quaife ATB uses a helical gear design to automatically distribute torque to the tyre with the most grip. Unlike plate-type units, it is smooth, progressive and quiet, so it suits daily use yet delivers serious performance when you push. Expect stronger drive off the line, faster corner exits, improved stability in the wet and fewer interventions from the electronics.

Vehicle fitment

For rear wheel drive BMW M140i and M240i with the B58 engine on the F-series platform: F20, F21, F22 and F23. If you are unsure about compatibility, contact us and we will help you confirm the correct unit.

Installation and support

We can supply and fit in-house at MJ Modifications in Warwickshire. For a fitting quote or to book your car in, email info@mjmodifications.co.uk. We have installed and run these units on our own B58 builds and customer cars, with consistently excellent feedback on traction, drivability and lap-to-lap consistency.

Notes

• Exchange scheme available – choose no exchange if you cannot return a core
• High performance bearings recommended for high mileage or high output cars
• Silent in operation and service free

Also searched as

BMW M140i rear axle upgrade, M240i final drive assembly, F20 F21 F22 F23 rear diff unit, torque biasing helical diff, BMW 1 Series performance rear end, BMW 2 Series traction upgrade, B58 rear drive unit, drop-in differential carrier, bolt-in pumpkin, fast road and track differential, open diff replacement for BMW M140i, open differential swap for BMW M240i, RWD BMW limited slip diff upgrade, Quaife ATB rear end for B58, BMW F-series rear axle assembly, performance rear differential for BMW 1 Series and 2 Series.