Funny noise when machine is emptying

My washing machine works fine,until it comes to emptying,it makes a very loud whiring noise,at first it was now and then but now its all the time,i`ve taken the back off it and taken out the small pump that is connected dirrectly to the outlet pipe at the base of the washing machine,just to check to see if this may be the problem,but that seams to be fine,the small wheel inside is free from any mess,please help,this noise is driving me mad,i`ve only had the machine about 18 months,thanks in advance to any suggestions