Pinion Shaft
WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The input shaft in a driving axle that is usually a part of the smaller driving or input hypoid gear of a ring and pinion gearset.