Spool Performance ATC-13 Stage 2 Transfer Case DIY Kit

The ATC-13 transfer case is a known weak point once you start pushing real power. The factory design simply isn’t built to handle sustained torque, aggressive launches, or high-load driving.

This kit fixes that—properly.

At the core of the upgrade is a fully redesigned billet hub machined from 4340 steel, then case hardened and nitrided to deliver exceptional surface hardness while maintaining core toughness. The main spline engagement surface has been optimized, increasing contact stability and reducing wear under high torque conditions—addressing one of the most common OEM failure points.

We didn’t stop there.

The internal oiling system has been completely reworked with CFD-optimized pathways, improving both lubrication and oil evacuation for cooling purposes. This allows for more consistent fluid distribution, reduced heat buildup, and improved durability during extended high-load operation—where the factory design typically falls short.

Clutch capacity is increased from 9 OEM frictions to 11, giving you a substantial jump in torque holding capability. The kit includes upgraded steels and our in-house developed FX-TRT high-coefficient friction material, specifically engineered for transfer case applications where heat, load, and consistency matter most.

The result is a transfer case that holds more power, runs cooler, and maintains consistent performance when it actually matters.

And like everything we build—this kit is designed for straightforward, plug-and-play installation with no unnecessary complications.

Key Features

4340 billet steel hub, case hardened and nitrided for maximum strength and durability
Optimized main spline engagement surface for improved load distribution and reduced wear
CFD-optimized oiling pathways for enhanced lubrication and oil evacuation (cooling)
Increased clutch capacity: 11 clutches vs 9 OEM
Upgraded steels for enhanced load handling
Proprietary FX-TRT high-friction material developed in-house
Designed for easy, plug-and-play installation

Vehicle Compatibility (ATC-13 Transfer Case)

This kit is designed for BMW vehicles equipped with the ATC-13 / ATC13-1 xDrive transfer case, found on most AWD BMW platforms 2015+ (primarily G-chassis and late F-chassis).

2 Series

G42 / G43 – M240i xDrive, 230i xDrive (2022+)

3 Series

G20 – 330i xDrive, M340i xDrive (2019+)
G80 – M3 Competition xDrive (2021+)

4 Series

G22 / G23 – 430i xDrive, M440i xDrive (2021+)
G26 – 4 Series Gran Coupe xDrive (2022+)
G82 / G83 – M4 Competition xDrive (2021+)

5 Series

G30 – 530i xDrive, 540i xDrive (2017+)
F90 – M5 (2018–2023)

6 Series

G32 – 640i xDrive Gran Turismo (2018+)

7 Series

G11 / G12 – 740i xDrive, 750i xDrive (2016+)
G70 – 7 Series xDrive (2024+)

8 Series

G14 / G15 / G16 – 840i xDrive, M850i xDrive (2019+)
F91 / F92 / F93 – M8 (2019+)

X Models (SUVs)

G01 – X3 xDrive (2018+)
F97 – X3M (2020+)
G02 – X4 xDrive (2019+)
F98 – X4M (2020+)
G05 – X5 xDrive (2019+)
F95 – X5M (2020+)
G06 – X6 xDrive (2020+)
F96 – X6M (2020+)
G07 – X7 xDrive (2019+)
G09 – XM (2024+)

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Spool Performance ATC-13 Stage 2 Transfer Case DIY Kit