I am getting a Cub Cadet 3648 Commercial Zero turn mower from my father. He has owned it about 4 years (purchased new) and has had constant problems with the pto clutch. He has replaced it every year he has owned it! They cost $400 just for the parts. I would like to know if anyone know of any modifactions that can be made to decrease the frequency of this problem. Ideas I am looking for is an aftermarket clutch that is better, a pto clutch from a different manufacturer that fits it that is better, etc. The engine is a Kawasaki 17 HP. Any advice is appreciated.