beko tumble dryer drum sticking?

i have taken all the dryer apart and removed the drum but whenever the dryer cools down the drum sticks again and need a full force shove to move before it goes round! it started to wear the motor and smelt of burning rubber which is how i noticed it had stopped working..... can anyone tell me how to stop the drum sticking? (it sticks around the edge that touchs the 'box' of the dryer so to speak.... help please!!)