The dryer rattles in the motor area also the dryer takes a long time to dry.

If it's noisy in the motor area you could have a bad blower wheel,if it's just spinning off the shaft this would make noise and no air movement.you need to send the model number so i can see what machine you have.also when was the last time you cleaned out the dryer and vent line?if it's gas it should be done once a year,electric once every two years.if the vent line is a long run from the back to the outside,i use a leaf blower and blow out the line.remove the vent line from the back of the dryer,stick the leaf blower in it and blow it out.then unplug the dryer,pull out the filter,clean out the duct that the filter slides into and vac out the cabinet where the motor is,if you have a shop vac put it on blow and blow off the motor and you can blow all the lint from the rear to the front and vac it up so you don't have to pull the drum out.

You have a bad blower . This piece slides onto the motor shaft and pulls the heat thru the drum and out thru the vent hose . It is easily replaced ( and inexpensive if you do it yourself ) by removing the front of the dryer .