Introducing the toughest 4L80-E input shaft available for 1,000 HP! 🙌 Input shaft failure is a major pain point in performance GM 4L80-E and 4L85-E transmissions running with extreme horsepower. OE and aftermarket shafts simply don’t hold up in these conditions, leading to spline twist and shaft breakage. Manufactured from an exceptionally tough, high-strength Aermet steel alloy with proprietary heat treatment (topped off with many more advanced features), this new extreme duty input shaft from