As you would know the weak spot on any steel fixture is the corners of the keyway and thats where they will break every time.
Normally this does not happen. The problem, in this case, is the cross section of the sprocket on a 1" shaft. If I would machine the pilot end of the PTO to .875" and use a 7/8" bore sprocket, then the problem would not have occurred. But I'm going to stick with the one-piece weldment because it's proven. I dyno tested a gearcase to failure once with that setup, driving it with my 806 and running my M&W PTO dyno with the output shaft. It took 475 lb-ft of torque @ 1,000 rpm, and what finally failed was the chain at 480 lb-ft of torque.
There's few automotive transmissions in cars that can handle that amount of torque.
--
Chris
