Drum not turning-very loud sound coming frm dryer when turned on

There could be multiple problems with you whirlpool dyer depending on the type of noise you are hearing. If the noise is a low grumble or loud buzzing sound this could indicate a bad motor. Which could explain you not hearing the drum turning. If however you hear a grating or grinding type noise but the drum is turning, this could indicate that something is rubbing or has become jammed inside the blower fan that circulates the air. if this is the case it too may have to be replaced. Also the drum can sometime come off the drum support rollers at the back of the dryer, but this is very uncommon, and only happens if they are very worn or broken. This can easily be diagnosed by a technician and if the motor is fine, will cost little to repair.Hope this helps.

Thanks

yes  replace the belt