Why is a well made, straight and correct input shaft important?
Input shafts serve many purposes including:

1. Transfer power from the converter to the input sun gear while in low gear.
2. Transfer power from the converter to the high gear hub in high gear.
3. Direct oil coming from the converter to the front ring on the shaft and out through the pump to the oil cooler.
4. Direct oil from the cooler between the 2 rings and down through the center of the shaft to lube and cool the direct clutches, gear set, output shaft bushing and the entire transmission.
5. Maintain proper oil pressure in the converter and cooler with its sized holes that are “downstream restrictions” to control the flow out of the converter.
6. Center and support the Input Sun Gear from its pitch diameter to the ½ diameter that goes into the bushing on the output shaft
7. Center and support the Output Sun Gear (flange gear) via the “wedding band”.

Which companies in the industry are capable of making input shafts properly? Who has the hobs, shapers and cutters to cut splines? Do they have the machines and the expertise that is required to manufacture this critical part? Can they properly heat treat it, straighten and finish grind it? Or, do they just buy it from someone and resell it? One thing is for sure: at ATI, if we have a problem, we have a REASON, not an EXCUSE, because we make it in-house from start to finish. We find the problems, not you. The bottom line is simple: Manufacturing technique for this product is critical. Material is critical. Heat-treat is critical.