Wavetrac Limited Slip Differential BMW 3 Series (E46/E9X) / 1 Series (E8X) / 5 Series (E60) 188K Axle Rear 3.15+ Ratio

Wavetrac Limited Slip Differential - BMW 3 Series (E46/E9X) / 1 Series (E8X) / 5 Series (E60) - 188K Axle Rear 3.15+ Ratio

The Wavetrac is a helical gear, torque-biasing limited slip differential that directly replaces the factory differential in the BMW 188K rear axle (3.15+ final drive) of the E46 and E9X 3 Series, E8X 1 Series, E60 5 Series and Z4. Unlike conventional helical LSDs, Wavetrac's patented design keeps driving the wheel with grip even when the other wheel is unloaded or in the air - where other helical diffs behave like an open diff. There are no clutch packs to wear, adjust or rebuild.

Note: Final drive ratio must be 3.15 or higher. Also suits the Z4 2.5i and 3.0i. Suits axles with a bolted ring gear; some E9X, E8X, E60 and Z4 axles have a factory-welded ring gear, which needs machining and a separate installation kit. Needs ARP ring gear bolt kit N.M12.150.24K.

Fitment & Identification

• E46 325i, 328i, 330i automatic 1998-2005 - bolted ring gear
• E9X 325i, 328i, 330i 2006+ - some ring gears may be welded
• E9X 335i automatic 09/2007+ - some ring gears may be welded
• E8X 135i automatic 2008+ - some ring gears may be welded
• E8X 128i 2008+ - some ring gears may be welded
• E60 525i, 528i, 530i automatic - some ring gears may be welded
• Z4 2.5i, 3.0i - some ring gears may be welded
• Axle: BMW 188K
• Final drive ratio must be 3.15+ - check the ratio stamped on your diff or in your vehicle build data
• Welded OEM ring gear assemblies need machining and an installation kit (sold separately)
• Position: Rear

Please confirm your gearbox or axle code, final drive ratio and model year before ordering. If you are unsure, send us your VIN and gearbox/axle code and we will confirm fitment.

What You'll Also Need

• Your factory ring gear, transferred from the original differential
• ARP ring gear bolt kit for BMW 188K / 215K axles (N.M12.150.24K, 10pc - torque 80 ft-lb with red Loctite)
• New carrier bearings are recommended when the differential is changed
• Gear oil to factory specification (see below)

Installation

Installation by a professional driveline specialist is always recommended. The ring gear is transferred to the Wavetrac and backlash and bearing preload are set to factory specification. No break-in is required for the Wavetrac itself - follow the break-in procedure only if a new ring and pinion is fitted at the same time.

Gear Oil

• Use the gear oil specified by your vehicle manufacturer - the Wavetrac is compatible with virtually all factory-fill gear oils
• Avoid gear oils with limited slip (friction modifier) additives - they reduce the friction a helical differential relies on
• Do NOT use Red Line ShockProof or similar oils - this voids the Wavetrac warranty
• For racing, Wavetrac recommends Motul synthetic high-performance gear oils

Strength & Maintenance

Wavetrac differentials use high-strength 9310 alloy steel gears in case-hardened billet or forged steel housings, assembled with ARP fasteners. In almost any gearbox or axle, the Wavetrac is not the limiting factor in torque capacity. There is no scheduled maintenance and no rebuilds are required.

Warranty

Wavetrac limited lifetime warranty against defects in manufacture, material, workmanship and wear-out, when used in the application it was designed for - including racing - and transferable to subsequent owners. Excludes differentials that are incorrectly installed, fitted to the wrong application, modified, or run in ShockProof-type oil. Proof of purchase from an authorised Wavetrac dealer is required.

Specifications

• Type: Helical gear torque-biasing limited slip differential
• Position: Rear
• Gearbox / axle: BMW 188K
• Drivetrain: RWD
• Final drive ratio: 3.15+
• Ring gear: Bolted (welded needs machining + install kit) - M12 bolts (N.M12.150.24K, 80 ft-lb)
• Gears: 9310 high-strength alloy steel
• Housing: Case-hardened billet or forged steel
• Fasteners: ARP
• Maintenance: Maintenance free — no rebuilds required
• Warranty: Wavetrac limited lifetime warranty
• Made in: USA
• Part number: 30.309.175WK

Need help confirming the right Wavetrac for your car? Contact our team at sales@chicaneaustralia.com.au.