Spool Performance – Mercedes AMG 725 9G FX-RT Upgraded Clutch Kit

Description

Spool Performance – Mercedes 725 9G FX-RT Upgraded Clutch Kit Note: Please email customer_service@spoolperformance.us for details on scheduling training for installation of this component. Rated for up to 1,700 Nm input torque The Mercedes 725 9G transmission is a strong unit from the factory—but once torque levels push past the mid-700 Nm, the stock frictions and limited plate counts begin to slip, especially under repeated high-load, high-temperature conditions. Spool Performance has developed a complete upgraded clutch system for the 725 9G using our FX-RT high-coefficient, high-energy friction material , the same proven technology that transformed the 8HP50 platform into a competition worthy transmission. This new kit increases both the coefficient of friction (+20%) and the clutch counts across all six elements , dramatically increasing the torque capacity of every gear. Clutch Count Increases Clutch Stock Upgraded Increase A 4 6 +2 B 4 7 +3 C 5 7 +2 D 6 9 +3 E 6 9 +3 F 7 10 +3 Combined with the FX-RT friction upgrade, the resulting torque-capacity increases are substantial. Torque Capacity Gains (Per Gear) Based on clutch engagement logic for the 9G and the combined friction + plate-count increases: Gear Engaged Clutches Torque Increase 1st B C E +68% 2nd C D E +68% 3rd B C D +68% 4th B C F +68% 5th B D F +71.4% 6th D E F +71.4% 7th B E F +71.4% 8th A E F +71.4% 9th A B F +71.4% Final Torque Rating The factory 725 9G is rated for 1000 Nm . With the FX-RT clutch packs installed: • 1st–4th gear clutch-limited rating: ≈1680 Nm • 5th–9th gear clutch-limited rating: ≈1714 Nm • Overall clutch-pack system capability: ≈1,700 Nm This upgrade raises the clutch-limited torque threshold by +68–71% , depending on gear. Why FX-RT? Our FX-RT friction material was engineered specifically for high-torque, high-energy, fast-shift transmissions. It has been proven in our 8HP50 kits , where customers reliably push 900–1000 Nm. Now the same technology elevates the Mercedes 725 9G into a new performance class. Benefits include: • 20% higher μ for dramatically improved static and dynamic holding power • Higher thermal stability under repeated high-load upshifts • Reduced shift flare and reduced clutch slip • Smoother, more consistent clutch apply characteristics Who This Kit Is For The Spool Performance 725 9G upgraded clutch kit is ideal for: • High-power M177 builds • GLE63 / GLS63 high-boost setups • Tuned E63 / S63 running hybrid turbos • Track-driven or heavy-use AMG applications • Anyone targeting 1000+ crank hp with headroom Your 725 9G is no longer the limiting factor. With Spool Performance FX-RT friction technology and increased clutch capacity, the transmission becomes capable of safely holding ~1700 Nm , giving your AMG the drivetrain headroom it needs to push big-power, high-boost builds confidently and repeatedly. What’s Included The Spool Performance 725 9G FX-RT Clutch Upgrade Kit includes all components required for a complete drop-in installation. No machining or custom fabrication is needed. • Clutch A [B08] Pack (6-plate upgrade) • 6 x FX-RT friction discs • 6 x Upgraded Steel plates • 1 x Custom Pressure Plate Clutch B [B05] Pack (7-plate upgrade) • 7 x FX-RT friction discs • 7 x steel plates • 1 x Custom Pressure Plate Clutch C [B06] Pack (7-plate upgrade) • 7 x FX-RT friction discs • 7 x steel plates • 1 x Custom Pressure Plate Clutch D [K81] Pack (9-plate upgrade) • 9 x FX-RT friction+steel internal spline discs • 9 FX-RT friction+steel external spline discs • 1 x Custom Pressure Plate Clutch E [K38] Pack (9-plate upgrade) • 9 x FX-RT friction discs • 9 x steel plates • 1 x Custom Pressure Plate Clutch F [K27] Pack (10-plate upgrade) • 10 x FX-RT friction discs • 10 x steel plates • 1 x Custom Pressure Plate Everything is pre-measured and packaged by clutch pack to ensure consistent clearances and simplified assembly. The kit is fully compatible with factory drums, pistons, and snap-ring locations.

Specifications