whats the problem with my servis 1500 washer?

My washing machine is washing the clothes ok. Although it is making a slight grinding noise as though something is catching. When it gets to spin, it turns but not at the full speed it used to. Even if we just put it on a rinse and spin after the wash. We are having to wring the clothes out manually. I thought it may be the pump or something so I took of all the pipes and nothing seemed to be blocked,however upon taking the pipe from the drum to the pump there was a clear plastic ball is this supposed to be there?I had a reply from someone who said it could possibly be the modules? If it is the modules where would I find them ?