Extreme Duty Input Shaft
Part No. 35280-02

For use with turbine support bushing in converter.

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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 35280-02 is ideal for any high-horsepower racing application. It has a 1-1/8" diameter, the largest size that fits within a stock style stator tube. Manufactured from 300M, high-strength steel with additional processing for resistance to fracture, this shaft strikes the perfect balance between strength and ease of installation.

It is intended to be used with aftermarket converters with internal turbine support. Its 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, 1-1/8" dia., 35-spline input shaft is 35% stronger than standard 1" shafts
  • High-strength 300M steel shaft undergoes additional processing to build in resistance to fracture
  • Ideal for any high-horsepower racing application

Using this shaft requires changing to a 35-spline turbine hub in the torque converter and use of pump cover big shaft stator support tube kit 28154S-125 with larger inner diameter.

  • Shaft Material: 300M
  • Shaft Dia.: 1.125"
  • Front Spline Tooth Count: 35
  • TH400 Extreme Duty Input Shaft 35280-02


TH400 Forward Drum & Input Shaft Upgrade Options