Either your front seal is old and worn (as dryer tumbles clothes are pulled between tumbler and front seal leaving a black streak on clothes) or the box were your heat enters the dryer has old debris from the previous loads baked onto it causing black marks as it tumbles.
kevin
April 2006
I can answer this question...
What could make my Maytag dryer leave black marks on clothes?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix tumble dryers.