Input shaft failure is a common problem in performance GM TH400 transmissions running with extreme horsepower. OE and aftermarket shafts simply don’t hold up in these conditions, leading to spline twist and shaft breakage.

Sonnax extreme duty input shaft 27280-02 is ideal for racing applications up to 4,000 HP where pumps, stators and converters are configured for 1-3/16" dia., 27-spline input shafts. It is manufactured from 300M, high-strength steel with additional processing for resistance to fracture. The forward drum spline is designed to be used with aftermarket drums with compatible 28-tooth spline, including Sonnax heavy duty forward drum 34554-01 and Smart-Tech^® drum module 34555-01K.

• Extreme duty, 1-3/16" dia., 27-spline input shaft
• High-strength 300M steel shaft undergoes additional processing to build in resistance to fracture
• Ideal for any high-horsepower racing application