Heat treat not right on some of the trannys, early 5 speeds had problems with clutch hub and tranny shafts breaking, also the sprockets would some times shear the locks, The MOCO came out with an upgrade for Big Twins as well as the Sportster line, I have repaired a number of the Sporsters in my time, JMO from what I have seen and worked on, I bet Chopper has a view on this, Capital Jack
