Product review (5 stars): Look for small cracks
When this part fails, it gives off a vibration sound that seems to be coming from the rear of the dryer.  After replacing the motor, heating element,and  installing the bearing rebuild kit, it was apparent that the only moving part left was the fan.  As one of the previous reviewers mentioned, look for small cracks on the hub of the fan.  I could not believe that those small cracks could cause so much noise and vibration. BTW, I was able to separate the fan from the motor shaft with locking pliers and an adjustable wrench.  I could not have completed these repairs without the you tube videos. Good Luck!!