TH400/TH425/4L80-E/4L85-E Transmission Sonnax Performance Extreme Duty Forward Clutch Hub Kit This extreme duty forward clutch hub is manufactured from forged 4140 steel and features nitrited and case-hardened splines to eliminate spline wear in extreme applications. Includes bearing between hub and direct clutch housing. The case-hardening at bearing surfaces is cut back to make further modifications easier. This forward clutch hub and bearing combination shifts the support of the forward clutch hub from the main shaft to the direct housing and sun gear shaft. Compared to OE or other replacement forward clutch hubs, Sonnax extreme duty forward clutch hub kit 34322-02K has an additional .025” thickness designed-in to reduce endplay and provide further endplay adjustment options. No machining is required for typical installation. Eliminates spline wear in extreme power and offroad applications Simple installation adds bearing and reduces unit endplay Easily modified for addition of second bearing. Contents Bearing Hub