Wavetrac Limited Slip Differential (LSD) Install Kit for BMW F22 228i & F30 328i 3.91 Final Drive Includes ARP Ring Gear Bolts Part No. 30.309.185WK

Wavetrac Diff Install Package for BMW F22 228i and F30 328i - 3.91 Ratio - Part No. 30.309.185WK

Give your BMW sharper drive out of bends, stronger traction and more consistent acceleration with this Wavetrac helical torque-biasing differential install package. Tailored for BMW 2 Series F22 228i and BMW 3 Series F30 328i models that use the 3.91 final drive, it is the proven rear axle upgrade for fast-road use, spirited street driving and track days while remaining perfectly civil for the daily commute.

We have installed and used these units ourselves and customer feedback has been outstanding. Expect confident power delivery, reduced inside wheelspin and a far more planted feel when you lean on the throttle mid-corner. The Wavetrac design offers real-world traction in situations where conventional gear-type units fade, delivering predictable, repeatable performance mile after mile.

Why this Wavetrac helical unit stands out

• Patented wave-cam technology helps maintain drive when one wheel is lightly loaded, improving launch and corner exit on mixed or low-grip surfaces.
• Case-hardened forged or billet steel bodies with 9310 steel gears provide exceptional strength and durability.
• No clutches or friction plates to wear, so it is engineered for long service life with minimal maintenance.
• Smoother, more consistent power delivery than an open rear diff for faster real-world pace and improved confidence.
• Refined behaviour for daily use with the toughness needed for performance driving.

What you receive

• Wavetrac helical differential core
• Your ring gear machined for correct fitment
• Precision-ground spacer ring where applicable
• Set of 10 high strength ARP ring gear bolts

Vehicle compatibility

• BMW F22 228i with 3.91 final drive
• BMW F30 328i with 3.91 final drive

If your search includes terms like BMW diff upgrade, helical LSD conversion, torque-biasing rear diff for F22 or F30, 3.91 BMW differential, or Wavetrac 30.309.185WK, this package is the correct match for the models and ratio listed above.

Part number

30.309.185WK

Fitting and support

Professional installation is recommended. For expert fitting, choose MJ Modifications in Warwickshire. We can supply, install and set up your Wavetrac differential for optimum performance. Request a fitting quote at info@mjmodifications.co.uk.

Pre-dispatch fitment check

To ensure compatibility, we verify your vehicle details before shipping. Provide your UK registration or the last 7 digits of your VIN at checkout and our team will confirm fitment.

Warranty

Wavetrac Differential Limited Lifetime Warranty.

Why buy from us

We have hands-on experience with these units and our customers consistently report stronger grip, cleaner power application and a clear step up in drivability and confidence. If you want a reliable rear differential upgrade that works brilliantly on British roads and performs on circuit days, this Wavetrac install package delivers.

Search terms to help you find this product: BMW 228i diff upgrade, BMW 328i diff upgrade, F22 differential conversion, F30 differential conversion, helical LSD for BMW, torque-biasing LSD, gear-driven LSD, rear axle 3.91, performance diff kit, ARP ring gear hardware, ARP ring bolts, BMW open diff replacement, track day differential, fast road rear diff, driveline upgrade, BMW F22 228i 3.91 ratio, BMW F30 328i 3.91 ratio, limited slip install package, diff swap kit, Wavetrac BMW 30.309.185WK.