2008-2021 Subaru STI
Upgrade your Subaru STI’s transmission with IAG’s 1st–6th Carbon Synchro Set—designed for smoother shifting, enhanced durability, and optimal performance whether rebuilding your gearbox or installing a performance drivetrain.
Enhanced Shift Quality & Reliability
Eliminates gear grinding and reduces wear on the transmission housing by replacing worn synchros with a full carbon-faced set.
Advanced Dual Carbon Friction Surfaces
Maximizes surface contact for faster, more precise shifts under aggressive driving conditions.
High-Strength Japanese Brass Construction
Precision-machined for durability and resistance to wear, delivering a robust shift feel.
Improved Shift Engagement
Larger friction surface area lowers shift force, providing a smooth, low-effort gear change experience.
Complete 1st–6th Gear Kit
Contains all required synchros—no need to source individual pieces or mix OEM parts.
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