excess dust and lint in cabinet[creda tvr2]?

Is there a dust gasket at front of drum?When i opened it up there was a round belt thingy which was too long to go around drum [could it be stretched].Also the drum will not turn,unless i gave it a start by hand[i had to defeat door lock to do this] then it runs until it reverses then same problem occurs, motor will hum until i give it a spin by hand.