Sonnax Forward Clutch Hub – GM TH400 / 4L80-E

Sonnax full forward clutch hub for GM TH400 and 4L80-E transmissions. Carbon steel construction designed to restore durability during rebuilds and performance upgrades.

If you’re inside a TH400 or 4L80-E, this is not a part you gamble on.

The Sonnax forward clutch hub is a full-hub replacement engineered to restore strength, alignment, and long-term durability in GM TH400 and 4L80-E transmissions. Manufactured from carbon steel, this hub is designed to handle the real-world loads that stock or worn hubs often fail under—especially in performance and heavy-duty applications.

Forward clutch hub failure is one of those problems that doesn’t give a warning—it just takes out the transmission. Replacing it during a rebuild is cheap insurance, especially when power levels, vehicle weight, or driving conditions push the limits of factory components.

This is a Sonnax solution—meaning it’s built by a company that specializes in fixing the weak points GM left behind.

What This Part Is For

• GM TH400 rebuilds
• GM 4L80-E rebuilds
• Replacing worn or damaged forward clutch hubs
• Performance, towing, street/strip, and heavy-duty applications
• Full forward clutch hub design
• Carbon steel construction for increased strength
• Designed for GM TH400 and 4L80-E transmissions
• Restores proper clutch engagement and durability
• Ideal upgrade during complete rebuilds

Why Sonnax

Sonnax doesn’t make parts to be “good enough.” They make parts to fix problems. This hub exists because forward clutch hub wear and failure is common in high-load GM automatics.

If you’re already rebuilding the transmission, installing the correct upgraded hub is how you avoid doing the job twice.

Fitment Notes

• Fits GM TH400 transmissions
• Fits GM 4L80-E transmissions
• Intended for professional rebuild or experienced DIY installation

SKU: 34322-01