Description 4L80-E, 4L85-E, TH400, TH425 Heavy Duty Forward Clutch Hub Part No. 34322-01 Sonnax heavy duty forward clutch hub 34322-01 is an ideal upgrade over OE hubs in GM TH400, TH425, 4L80-E and 4L85-E applications. It is made from 1045 steel forging and features a thicker cross-section for increased strength. Made from forged 1045 steel Thicker cross-section for increased strength Added durability for daily drivers, work trucks and mild performance applications