Let's just say that gearbox failure on this machine is rare, and leave it there.
Nine times out of 10, noises are more likely to be caused by belt, pulley or clutch issues on this particular machine. Check the length of the drive belt to ensure that there are no notches worn in it. The spin clutch is attached to the motor, and is a replaceable part. Suggest you punch your model number into the parts lookup and have a good looksee at the breakdown. You understand that even though we are mostly experts here, we can't hear the noise for you and make a determination. With the front off of the machine, it should be fairly easy to narrow down the location of the sound.