T-5 problem

Well while I was driving the other day the shaft that goes over the input shaft broke. Well I had one from another t-5 i had and put it on. The first day it ran fine. Now 2 days later I am having a loud bearing noise, and a vibration when slowing down in gear. Not sure if this part I put on is wrong or not. It came from a 4cyl t-5 that i had outback. A local shop said they were the same as a v8 t-5 and it would work.
What would cause this? When the shaft broke could it have messed the input shaft or the bearing on it? And why did this shaft break to begin with? I installed a new throwout bearing. Anyone have any ideas or have this happen to them? Will I need to replace the bearing or get another shaft part?