The blower assy fan in my dryer had separated where the plastic is molded around the outside edges of the fan blades (the ring) to hold them true. Although the dryer would still work it was very noisy because this let a few of the blades rub on the housing which was very loud. Once replacing this all was quite again. The hardest part in my opinion was getting the old fan loose from the motor shaft. Since it is a plastic nut molded with the fan you need to be sure you find a socket that fits very tight so as to not slip around and knock off the corners of the plastic nut. I'm not sure how you would get this off without taking the motor completely out if you were to strip it. Much easier to take your time and figure this one out. Reinstalling the new one was not difficult at all. Be sure to not damage the heat sensor in the old housing so you can transfer it to the new one. This part appears to be exactly the same as what came out of the dryer in my opinion and fit exactly the same. Good Luck! :)
I was ready to buy a new motor until I read a review from a guy that said he replaced both and discovered that it was the blower creating the noise not the motor. If your dryer is noisy, check the rollers, if ok look for hairline cracks on the blower fan in the center where the shaft attaches.