02 One change that we did have to make was the clutch disc and throw out bearing. Our factory transmission used a 23-spline input shaft, and the new Passon unit has an 18-spline input shaft. Passon Performance chose to use an 18-spline input, because 18-spline is considerably stronger. With the transmission rated for a continuous 700 lb/ft., strength is the operative word. Passon also recommends that if changing the clutch disc, the pressure plate should also be changed.