Spool Performance ATC-13 Stage 2 Transfer Case DIY Kit

Spool Performance ATC-13 Stage 2 Transfer Case DIY Kit

The ATC-13 transfer case can become a weak point when torque, repeated launches and sustained load increase. The Spool Stage 2 kit strengthens the mechanical drive and clutch pack while revising oil flow through the unit.

Its new hub is machined from 4340 billet steel, case-hardened and nitrided. The main spline engagement is enlarged for better load distribution. Clutch capacity increases from nine frictions to eleven, using Spool FX-TRT material and upgraded steels.

Main upgrades

• 4340 billet-steel hub with case hardening and nitriding
• Optimised spline engagement to reduce wear
• CFD-developed oil paths for lubrication and cooling
• Eleven friction plates instead of nine
• Upgraded steels and high-coefficient FX-TRT friction material

Fitment is determined by the ATC-13 / ATC13-1 transfer-case type. The same vehicle model may use a different case, so confirm the tag or part number before ordering.

Example vehicle fitment

• G42 / G43 – M240i xDrive, 230i xDrive (2022–)
• G20 – 330i xDrive, M340i xDrive (2019–)
• G80 – M3 Competition xDrive (2021–)
• G22 / G23 – 430i xDrive, M440i xDrive (2021–)
• G26 – 4 Series Gran Coupe xDrive (2022–)
• G82 / G83 – M4 Competition xDrive (2021–)
• G30 – 530i xDrive, 540i xDrive (2017–)
• F90 – M5 (2018–2023)
• G32 – 640i xDrive Gran Turismo (2018–)
• G11 / G12 – 740i xDrive, 750i xDrive (2016–)
• G70 – 7 Series xDrive (2024–)
• G14 / G15 / G16 – 840i xDrive, M850i xDrive (2019–)
• F91 / F92 / F93 – M8 (2019–)
• G01 – X3 xDrive (2018–)
• F97 – X3M (2020–)
• G02 – X4 xDrive (2019–)

Always confirm the engine, chassis, model year and part-specific fitment before ordering. Not every version within a model range necessarily uses the same part.