We begin with premium grade 300M steel round stock manufactured right here in the USA. After CNC-machining each shaft right here 100% in-house and broaching each spline section, we then incorporate a proprietary 13-step (!!!) heat treatment process.

We don’t stop there, either! After our custom heat treating process is completed, we then subject each shaft to nitride treatment. Our nitriding process increases surface hardness, improves tensile and torsional strength, and increases wear resistance.

After nitriding, each 4L80E input shaft is precision ground to exacting tolerances for better-than-OEM fit and finish!

There are cheaper 4L80E billet input shafts out there, but ask yourself what steps are being skipped to manufacture a cheaper shaft before spending your hard-earned money on a potentially inferior product.