Sonnax 34322-02K Extreme Duty Forward Clutch Hub Kit

The Sonnax 34322-02K Extreme Duty Forward Clutch Hub Kit is engineered for high-performance and extreme-duty applications in GM TH400, TH425, 4L80-E, and 4L85-E transmissions. This heavy-duty upgrade is designed to eliminate spline wear in extreme power and off-road applications where stock components fail.

Construction and Materials:

• Manufactured from forged 4140 steel for maximum strength and durability
• Features nitrided and case-hardened splines to prevent spline wear under extreme loads
• Case-hardening at bearing surfaces is removed to make further modifications easier
• Precision-machined to exacting tolerances for reliable performance

Key Features:

• Includes bearing between hub and direct clutch housing for improved support
• Shifts forward clutch hub support from main shaft to direct housing and sun gear shaft
• Additional 0.025" thickness designed-in to reduce endplay and provide adjustment options
• Hub outer spline length increased by 0.055" to allow additional clutch with shortened piston
• No machining required for typical installation

What's Included: Forward clutch hub and bearing assembly.

Compatibility Note: Not compatible with 1964-1966 TH400 main shafts with major diameter of spline approximately 0.980". To use this hub in early units, a 1967-later main shaft with major diameter of approximately 0.970" must be used.